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Diffstat (limited to 'examples/redis-unstable/src/ziplist.c')
| -rw-r--r-- | examples/redis-unstable/src/ziplist.c | 2665 |
1 files changed, 0 insertions, 2665 deletions
diff --git a/examples/redis-unstable/src/ziplist.c b/examples/redis-unstable/src/ziplist.c deleted file mode 100644 index db582b3..0000000 --- a/examples/redis-unstable/src/ziplist.c +++ /dev/null @@ -1,2665 +0,0 @@ -/* The ziplist is a specially encoded dually linked list that is designed - * to be very memory efficient. It stores both strings and integer values, - * where integers are encoded as actual integers instead of a series of - * characters. It allows push and pop operations on either side of the list - * in O(1) time. However, because every operation requires a reallocation of - * the memory used by the ziplist, the actual complexity is related to the - * amount of memory used by the ziplist. - * - * ---------------------------------------------------------------------------- - * - * ZIPLIST OVERALL LAYOUT - * ====================== - * - * The general layout of the ziplist is as follows: - * - * <zlbytes> <zltail> <zllen> <entry> <entry> ... <entry> <zlend> - * - * NOTE: all fields are stored in little endian, if not specified otherwise. - * - * <uint32_t zlbytes> is an unsigned integer to hold the number of bytes that - * the ziplist occupies, including the four bytes of the zlbytes field itself. - * This value needs to be stored to be able to resize the entire structure - * without the need to traverse it first. - * - * <uint32_t zltail> is the offset to the last entry in the list. This allows - * a pop operation on the far side of the list without the need for full - * traversal. - * - * <uint16_t zllen> is the number of entries. When there are more than - * 2^16-2 entries, this value is set to 2^16-1 and we need to traverse the - * entire list to know how many items it holds. - * - * <uint8_t zlend> is a special entry representing the end of the ziplist. - * Is encoded as a single byte equal to 255. No other normal entry starts - * with a byte set to the value of 255. - * - * ZIPLIST ENTRIES - * =============== - * - * Every entry in the ziplist is prefixed by metadata that contains two pieces - * of information. First, the length of the previous entry is stored to be - * able to traverse the list from back to front. Second, the entry encoding is - * provided. It represents the entry type, integer or string, and in the case - * of strings it also represents the length of the string payload. - * So a complete entry is stored like this: - * - * <prevlen> <encoding> <entry-data> - * - * Sometimes the encoding represents the entry itself, like for small integers - * as we'll see later. In such a case the <entry-data> part is missing, and we - * could have just: - * - * <prevlen> <encoding> - * - * The length of the previous entry, <prevlen>, is encoded in the following way: - * If this length is smaller than 254 bytes, it will only consume a single - * byte representing the length as an unsigned 8 bit integer. When the length - * is greater than or equal to 254, it will consume 5 bytes. The first byte is - * set to 254 (FE) to indicate a larger value is following. The remaining 4 - * bytes take the length of the previous entry as value. - * - * So practically an entry is encoded in the following way: - * - * <prevlen from 0 to 253> <encoding> <entry> - * - * Or alternatively if the previous entry length is greater than 253 bytes - * the following encoding is used: - * - * 0xFE <4 bytes unsigned little endian prevlen> <encoding> <entry> - * - * The encoding field of the entry depends on the content of the - * entry. When the entry is a string, the first 2 bits of the encoding first - * byte will hold the type of encoding used to store the length of the string, - * followed by the actual length of the string. When the entry is an integer - * the first 2 bits are both set to 1. The following 2 bits are used to specify - * what kind of integer will be stored after this header. An overview of the - * different types and encodings is as follows. The first byte is always enough - * to determine the kind of entry. - * - * |00pppppp| - 1 byte - * String value with length less than or equal to 63 bytes (6 bits). - * "pppppp" represents the unsigned 6 bit length. - * |01pppppp|qqqqqqqq| - 2 bytes - * String value with length less than or equal to 16383 bytes (14 bits). - * IMPORTANT: The 14 bit number is stored in big endian. - * |10000000|qqqqqqqq|rrrrrrrr|ssssssss|tttttttt| - 5 bytes - * String value with length greater than or equal to 16384 bytes. - * Only the 4 bytes following the first byte represents the length - * up to 2^32-1. The 6 lower bits of the first byte are not used and - * are set to zero. - * IMPORTANT: The 32 bit number is stored in big endian. - * |11000000| - 3 bytes - * Integer encoded as int16_t (2 bytes). - * |11010000| - 5 bytes - * Integer encoded as int32_t (4 bytes). - * |11100000| - 9 bytes - * Integer encoded as int64_t (8 bytes). - * |11110000| - 4 bytes - * Integer encoded as 24 bit signed (3 bytes). - * |11111110| - 2 bytes - * Integer encoded as 8 bit signed (1 byte). - * |1111xxxx| - (with xxxx between 0001 and 1101) immediate 4 bit integer. - * Unsigned integer from 0 to 12. The encoded value is actually from - * 1 to 13 because 0000 and 1111 can not be used, so 1 should be - * subtracted from the encoded 4 bit value to obtain the right value. - * |11111111| - End of ziplist special entry. - * - * Like for the ziplist header, all the integers are represented in little - * endian byte order, even when this code is compiled in big endian systems. - * - * EXAMPLES OF ACTUAL ZIPLISTS - * =========================== - * - * The following is a ziplist containing the two elements representing - * the strings "2" and "5". It is composed of 15 bytes, that we visually - * split into sections: - * - * [0f 00 00 00] [0c 00 00 00] [02 00] [00 f3] [02 f6] [ff] - * | | | | | | - * zlbytes zltail zllen "2" "5" end - * - * The first 4 bytes represent the number 15, that is the number of bytes - * the whole ziplist is composed of. The second 4 bytes are the offset - * at which the last ziplist entry is found, that is 12, in fact the - * last entry, that is "5", is at offset 12 inside the ziplist. - * The next 16 bit integer represents the number of elements inside the - * ziplist, its value is 2 since there are just two elements inside. - * Finally "00 f3" is the first entry representing the number 2. It is - * composed of the previous entry length, which is zero because this is - * our first entry, and the byte F3 which corresponds to the encoding - * |1111xxxx| with xxxx between 0001 and 1101. We need to remove the "F" - * higher order bits 1111, and subtract 1 from the "3", so the entry value - * is "2". The next entry has a prevlen of 02, since the first entry is - * composed of exactly two bytes. The entry itself, F6, is encoded exactly - * like the first entry, and 6-1 = 5, so the value of the entry is 5. - * Finally the special entry FF signals the end of the ziplist. - * - * Adding another element to the above string with the value "Hello World" - * allows us to show how the ziplist encodes small strings. We'll just show - * the hex dump of the entry itself. Imagine the bytes as following the - * entry that stores "5" in the ziplist above: - * - * [02] [0b] [48 65 6c 6c 6f 20 57 6f 72 6c 64] - * - * The first byte, 02, is the length of the previous entry. The next - * byte represents the encoding in the pattern |00pppppp| that means - * that the entry is a string of length <pppppp>, so 0B means that - * an 11 bytes string follows. From the third byte (48) to the last (64) - * there are just the ASCII characters for "Hello World". - * - * ---------------------------------------------------------------------------- - * - * Copyright (c) 2009-2012, Pieter Noordhuis <pcnoordhuis at gmail dot com> - * Copyright (c) 2009-current, Redis Ltd. - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions are met: - * - * * Redistributions of source code must retain the above copyright notice, - * this list of conditions and the following disclaimer. - * * Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * * Neither the name of Redis nor the names of its contributors may be used - * to endorse or promote products derived from this software without - * specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" - * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE - * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR - * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF - * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS - * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN - * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) - * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE - * POSSIBILITY OF SUCH DAMAGE. - */ - -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <stdint.h> -#include <limits.h> -#include "zmalloc.h" -#include "util.h" -#include "ziplist.h" -#include "config.h" -#include "endianconv.h" -#include "redisassert.h" - -#define ZIP_END 255 /* Special "end of ziplist" entry. */ -#define ZIP_BIG_PREVLEN 254 /* ZIP_BIG_PREVLEN - 1 is the max number of bytes of - the previous entry, for the "prevlen" field prefixing - each entry, to be represented with just a single byte. - Otherwise it is represented as FE AA BB CC DD, where - AA BB CC DD are a 4 bytes unsigned integer - representing the previous entry len. */ - -/* Different encoding/length possibilities */ -#define ZIP_STR_MASK 0xc0 -#define ZIP_INT_MASK 0x30 -#define ZIP_STR_06B (0 << 6) -#define ZIP_STR_14B (1 << 6) -#define ZIP_STR_32B (2 << 6) -#define ZIP_INT_16B (0xc0 | 0<<4) -#define ZIP_INT_32B (0xc0 | 1<<4) -#define ZIP_INT_64B (0xc0 | 2<<4) -#define ZIP_INT_24B (0xc0 | 3<<4) -#define ZIP_INT_8B 0xfe - -/* 4 bit integer immediate encoding |1111xxxx| with xxxx between - * 0001 and 1101. */ -#define ZIP_INT_IMM_MASK 0x0f /* Mask to extract the 4 bits value. To add - one is needed to reconstruct the value. */ -#define ZIP_INT_IMM_MIN 0xf1 /* 11110001 */ -#define ZIP_INT_IMM_MAX 0xfd /* 11111101 */ - -#define INT24_MAX 0x7fffff -#define INT24_MIN (-INT24_MAX - 1) - -/* Macro to determine if the entry is a string. String entries never start - * with "11" as most significant bits of the first byte. */ -#define ZIP_IS_STR(enc) (((enc) & ZIP_STR_MASK) < ZIP_STR_MASK) - -/* Utility macros.*/ - -/* Return total bytes a ziplist is composed of. */ -#define ZIPLIST_BYTES(zl) (*((uint32_t*)(zl))) - -/* Return the offset of the last item inside the ziplist. */ -#define ZIPLIST_TAIL_OFFSET(zl) (*((uint32_t*)((zl)+sizeof(uint32_t)))) - -/* Return the length of a ziplist, or UINT16_MAX if the length cannot be - * determined without scanning the whole ziplist. */ -#define ZIPLIST_LENGTH(zl) (*((uint16_t*)((zl)+sizeof(uint32_t)*2))) - -/* The size of a ziplist header: two 32 bit integers for the total - * bytes count and last item offset. One 16 bit integer for the number - * of items field. */ -#define ZIPLIST_HEADER_SIZE (sizeof(uint32_t)*2+sizeof(uint16_t)) - -/* Size of the "end of ziplist" entry. Just one byte. */ -#define ZIPLIST_END_SIZE (sizeof(uint8_t)) - -/* Return the pointer to the first entry of a ziplist. */ -#define ZIPLIST_ENTRY_HEAD(zl) ((zl)+ZIPLIST_HEADER_SIZE) - -/* Return the pointer to the last entry of a ziplist, using the - * last entry offset inside the ziplist header. */ -#define ZIPLIST_ENTRY_TAIL(zl) ((zl)+intrev32ifbe(ZIPLIST_TAIL_OFFSET(zl))) - -/* Return the pointer to the last byte of a ziplist, which is, the - * end of ziplist FF entry. */ -#define ZIPLIST_ENTRY_END(zl) ((zl)+intrev32ifbe(ZIPLIST_BYTES(zl))-ZIPLIST_END_SIZE) - -/* Increment the number of items field in the ziplist header. Note that this - * macro should never overflow the unsigned 16 bit integer, since entries are - * always pushed one at a time. When UINT16_MAX is reached we want the count - * to stay there to signal that a full scan is needed to get the number of - * items inside the ziplist. */ -#define ZIPLIST_INCR_LENGTH(zl,incr) { \ - if (intrev16ifbe(ZIPLIST_LENGTH(zl)) < UINT16_MAX) \ - ZIPLIST_LENGTH(zl) = intrev16ifbe(intrev16ifbe(ZIPLIST_LENGTH(zl))+incr); \ -} - -/* Don't let ziplists grow over 1GB in any case, don't wanna risk overflow in - * zlbytes */ -#define ZIPLIST_MAX_SAFETY_SIZE (1<<30) -int ziplistSafeToAdd(unsigned char* zl, size_t add) { - size_t len = zl? ziplistBlobLen(zl): 0; - if (len + add > ZIPLIST_MAX_SAFETY_SIZE) - return 0; - return 1; -} - - -/* We use this function to receive information about a ziplist entry. - * Note that this is not how the data is actually encoded, is just what we - * get filled by a function in order to operate more easily. */ -typedef struct zlentry { - unsigned int prevrawlensize; /* Bytes used to encode the previous entry len*/ - unsigned int prevrawlen; /* Previous entry len. */ - unsigned int lensize; /* Bytes used to encode this entry type/len. - For example strings have a 1, 2 or 5 bytes - header. Integers always use a single byte.*/ - unsigned int len; /* Bytes used to represent the actual entry. - For strings this is just the string length - while for integers it is 1, 2, 3, 4, 8 or - 0 (for 4 bit immediate) depending on the - number range. */ - unsigned int headersize; /* prevrawlensize + lensize. */ - unsigned char encoding; /* Set to ZIP_STR_* or ZIP_INT_* depending on - the entry encoding. However for 4 bits - immediate integers this can assume a range - of values and must be range-checked. */ - unsigned char *p; /* Pointer to the very start of the entry, that - is, this points to prev-entry-len field. */ -} zlentry; - -#define ZIPLIST_ENTRY_ZERO(zle) { \ - (zle)->prevrawlensize = (zle)->prevrawlen = 0; \ - (zle)->lensize = (zle)->len = (zle)->headersize = 0; \ - (zle)->encoding = 0; \ - (zle)->p = NULL; \ -} - -/* Extract the encoding from the byte pointed by 'ptr' and set it into - * 'encoding' field of the zlentry structure. */ -#define ZIP_ENTRY_ENCODING(ptr, encoding) do { \ - (encoding) = ((ptr)[0]); \ - if ((encoding) < ZIP_STR_MASK) (encoding) &= ZIP_STR_MASK; \ -} while(0) - -#define ZIP_ENCODING_SIZE_INVALID 0xff -/* Return the number of bytes required to encode the entry type + length. - * On error, return ZIP_ENCODING_SIZE_INVALID */ -static inline unsigned int zipEncodingLenSize(unsigned char encoding) { - if (encoding == ZIP_INT_16B || encoding == ZIP_INT_32B || - encoding == ZIP_INT_24B || encoding == ZIP_INT_64B || - encoding == ZIP_INT_8B) - return 1; - if (encoding >= ZIP_INT_IMM_MIN && encoding <= ZIP_INT_IMM_MAX) - return 1; - if (encoding == ZIP_STR_06B) - return 1; - if (encoding == ZIP_STR_14B) - return 2; - if (encoding == ZIP_STR_32B) - return 5; - return ZIP_ENCODING_SIZE_INVALID; -} - -#define ZIP_ASSERT_ENCODING(encoding) do { \ - assert(zipEncodingLenSize(encoding) != ZIP_ENCODING_SIZE_INVALID); \ -} while (0) - -/* Return bytes needed to store integer encoded by 'encoding' */ -static inline unsigned int zipIntSize(unsigned char encoding) { - switch(encoding) { - case ZIP_INT_8B: return 1; - case ZIP_INT_16B: return 2; - case ZIP_INT_24B: return 3; - case ZIP_INT_32B: return 4; - case ZIP_INT_64B: return 8; - } - if (encoding >= ZIP_INT_IMM_MIN && encoding <= ZIP_INT_IMM_MAX) - return 0; /* 4 bit immediate */ - /* bad encoding, covered by a previous call to ZIP_ASSERT_ENCODING */ - redis_unreachable(); - return 0; -} - -/* Write the encoding header of the entry in 'p'. If p is NULL it just returns - * the amount of bytes required to encode such a length. Arguments: - * - * 'encoding' is the encoding we are using for the entry. It could be - * ZIP_INT_* or ZIP_STR_* or between ZIP_INT_IMM_MIN and ZIP_INT_IMM_MAX - * for single-byte small immediate integers. - * - * 'rawlen' is only used for ZIP_STR_* encodings and is the length of the - * string that this entry represents. - * - * The function returns the number of bytes used by the encoding/length - * header stored in 'p'. */ -unsigned int zipStoreEntryEncoding(unsigned char *p, unsigned char encoding, unsigned int rawlen) { - unsigned char len = 1, buf[5]; - - if (ZIP_IS_STR(encoding)) { - /* Although encoding is given it may not be set for strings, - * so we determine it here using the raw length. */ - if (rawlen <= 0x3f) { - if (!p) return len; - buf[0] = ZIP_STR_06B | rawlen; - } else if (rawlen <= 0x3fff) { - len += 1; - if (!p) return len; - buf[0] = ZIP_STR_14B | ((rawlen >> 8) & 0x3f); - buf[1] = rawlen & 0xff; - } else { - len += 4; - if (!p) return len; - buf[0] = ZIP_STR_32B; - buf[1] = (rawlen >> 24) & 0xff; - buf[2] = (rawlen >> 16) & 0xff; - buf[3] = (rawlen >> 8) & 0xff; - buf[4] = rawlen & 0xff; - } - } else { - /* Implies integer encoding, so length is always 1. */ - if (!p) return len; - buf[0] = encoding; - } - - /* Store this length at p. */ - memcpy(p,buf,len); - return len; -} - -/* Decode the entry encoding type and data length (string length for strings, - * number of bytes used for the integer for integer entries) encoded in 'ptr'. - * The 'encoding' variable is input, extracted by the caller, the 'lensize' - * variable will hold the number of bytes required to encode the entry - * length, and the 'len' variable will hold the entry length. - * On invalid encoding error, lensize is set to 0. */ -#define ZIP_DECODE_LENGTH(ptr, encoding, lensize, len) do { \ - if ((encoding) < ZIP_STR_MASK) { \ - if ((encoding) == ZIP_STR_06B) { \ - (lensize) = 1; \ - (len) = (ptr)[0] & 0x3f; \ - } else if ((encoding) == ZIP_STR_14B) { \ - (lensize) = 2; \ - (len) = (((ptr)[0] & 0x3f) << 8) | (ptr)[1]; \ - } else if ((encoding) == ZIP_STR_32B) { \ - (lensize) = 5; \ - (len) = ((uint32_t)(ptr)[1] << 24) | \ - ((uint32_t)(ptr)[2] << 16) | \ - ((uint32_t)(ptr)[3] << 8) | \ - ((uint32_t)(ptr)[4]); \ - } else { \ - (lensize) = 0; /* bad encoding, should be covered by a previous */ \ - (len) = 0; /* ZIP_ASSERT_ENCODING / zipEncodingLenSize, or */ \ - /* match the lensize after this macro with 0. */ \ - } \ - } else { \ - (lensize) = 1; \ - if ((encoding) == ZIP_INT_8B) (len) = 1; \ - else if ((encoding) == ZIP_INT_16B) (len) = 2; \ - else if ((encoding) == ZIP_INT_24B) (len) = 3; \ - else if ((encoding) == ZIP_INT_32B) (len) = 4; \ - else if ((encoding) == ZIP_INT_64B) (len) = 8; \ - else if (encoding >= ZIP_INT_IMM_MIN && encoding <= ZIP_INT_IMM_MAX) \ - (len) = 0; /* 4 bit immediate */ \ - else \ - (lensize) = (len) = 0; /* bad encoding */ \ - } \ -} while(0) - -/* Encode the length of the previous entry and write it to "p". This only - * uses the larger encoding (required in __ziplistCascadeUpdate). */ -int zipStorePrevEntryLengthLarge(unsigned char *p, unsigned int len) { - uint32_t u32; - if (p != NULL) { - p[0] = ZIP_BIG_PREVLEN; - u32 = len; - memcpy(p+1,&u32,sizeof(u32)); - memrev32ifbe(p+1); - } - return 1 + sizeof(uint32_t); -} - -/* Encode the length of the previous entry and write it to "p". Return the - * number of bytes needed to encode this length if "p" is NULL. */ -unsigned int zipStorePrevEntryLength(unsigned char *p, unsigned int len) { - if (p == NULL) { - return (len < ZIP_BIG_PREVLEN) ? 1 : sizeof(uint32_t) + 1; - } else { - if (len < ZIP_BIG_PREVLEN) { - p[0] = len; - return 1; - } else { - return zipStorePrevEntryLengthLarge(p,len); - } - } -} - -/* Return the number of bytes used to encode the length of the previous - * entry. The length is returned by setting the var 'prevlensize'. */ -#define ZIP_DECODE_PREVLENSIZE(ptr, prevlensize) do { \ - if ((ptr)[0] < ZIP_BIG_PREVLEN) { \ - (prevlensize) = 1; \ - } else { \ - (prevlensize) = 5; \ - } \ -} while(0) - -/* Return the length of the previous element, and the number of bytes that - * are used in order to encode the previous element length. - * 'ptr' must point to the prevlen prefix of an entry (that encodes the - * length of the previous entry in order to navigate the elements backward). - * The length of the previous entry is stored in 'prevlen', the number of - * bytes needed to encode the previous entry length are stored in - * 'prevlensize'. */ -#define ZIP_DECODE_PREVLEN(ptr, prevlensize, prevlen) do { \ - ZIP_DECODE_PREVLENSIZE(ptr, prevlensize); \ - if ((prevlensize) == 1) { \ - (prevlen) = (ptr)[0]; \ - } else { /* prevlensize == 5 */ \ - (prevlen) = ((ptr)[4] << 24) | \ - ((ptr)[3] << 16) | \ - ((ptr)[2] << 8) | \ - ((ptr)[1]); \ - } \ -} while(0) - -/* Given a pointer 'p' to the prevlen info that prefixes an entry, this - * function returns the difference in number of bytes needed to encode - * the prevlen if the previous entry changes of size. - * - * So if A is the number of bytes used right now to encode the 'prevlen' - * field. - * - * And B is the number of bytes that are needed in order to encode the - * 'prevlen' if the previous element will be updated to one of size 'len'. - * - * Then the function returns B - A - * - * So the function returns a positive number if more space is needed, - * a negative number if less space is needed, or zero if the same space - * is needed. */ -int zipPrevLenByteDiff(unsigned char *p, unsigned int len) { - unsigned int prevlensize; - ZIP_DECODE_PREVLENSIZE(p, prevlensize); - return zipStorePrevEntryLength(NULL, len) - prevlensize; -} - -/* Check if string pointed to by 'entry' can be encoded as an integer. - * Stores the integer value in 'v' and its encoding in 'encoding'. */ -int zipTryEncoding(unsigned char *entry, unsigned int entrylen, long long *v, unsigned char *encoding) { - long long value; - - if (entrylen >= 32 || entrylen == 0) return 0; - if (string2ll((char*)entry,entrylen,&value)) { - /* Great, the string can be encoded. Check what's the smallest - * of our encoding types that can hold this value. */ - if (value >= 0 && value <= 12) { - *encoding = ZIP_INT_IMM_MIN+value; - } else if (value >= INT8_MIN && value <= INT8_MAX) { - *encoding = ZIP_INT_8B; - } else if (value >= INT16_MIN && value <= INT16_MAX) { - *encoding = ZIP_INT_16B; - } else if (value >= INT24_MIN && value <= INT24_MAX) { - *encoding = ZIP_INT_24B; - } else if (value >= INT32_MIN && value <= INT32_MAX) { - *encoding = ZIP_INT_32B; - } else { - *encoding = ZIP_INT_64B; - } - *v = value; - return 1; - } - return 0; -} - -/* Store integer 'value' at 'p', encoded as 'encoding' */ -void zipSaveInteger(unsigned char *p, int64_t value, unsigned char encoding) { - int16_t i16; - int32_t i32; - int64_t i64; - if (encoding == ZIP_INT_8B) { - ((int8_t*)p)[0] = (int8_t)value; - } else if (encoding == ZIP_INT_16B) { - i16 = value; - memcpy(p,&i16,sizeof(i16)); - memrev16ifbe(p); - } else if (encoding == ZIP_INT_24B) { - i32 = ((uint64_t)value)<<8; - memrev32ifbe(&i32); - memcpy(p,((uint8_t*)&i32)+1,sizeof(i32)-sizeof(uint8_t)); - } else if (encoding == ZIP_INT_32B) { - i32 = value; - memcpy(p,&i32,sizeof(i32)); - memrev32ifbe(p); - } else if (encoding == ZIP_INT_64B) { - i64 = value; - memcpy(p,&i64,sizeof(i64)); - memrev64ifbe(p); - } else if (encoding >= ZIP_INT_IMM_MIN && encoding <= ZIP_INT_IMM_MAX) { - /* Nothing to do, the value is stored in the encoding itself. */ - } else { - assert(NULL); - } -} - -/* Read integer encoded as 'encoding' from 'p' */ -int64_t zipLoadInteger(unsigned char *p, unsigned char encoding) { - int16_t i16; - int32_t i32; - int64_t i64, ret = 0; - if (encoding == ZIP_INT_8B) { - ret = ((int8_t*)p)[0]; - } else if (encoding == ZIP_INT_16B) { - memcpy(&i16,p,sizeof(i16)); - memrev16ifbe(&i16); - ret = i16; - } else if (encoding == ZIP_INT_32B) { - memcpy(&i32,p,sizeof(i32)); - memrev32ifbe(&i32); - ret = i32; - } else if (encoding == ZIP_INT_24B) { - i32 = 0; - memcpy(((uint8_t*)&i32)+1,p,sizeof(i32)-sizeof(uint8_t)); - memrev32ifbe(&i32); - ret = i32>>8; - } else if (encoding == ZIP_INT_64B) { - memcpy(&i64,p,sizeof(i64)); - memrev64ifbe(&i64); - ret = i64; - } else if (encoding >= ZIP_INT_IMM_MIN && encoding <= ZIP_INT_IMM_MAX) { - ret = (encoding & ZIP_INT_IMM_MASK)-1; - } else { - assert(NULL); - } - return ret; -} - -/* Fills a struct with all information about an entry. - * This function is the "unsafe" alternative to the one below. - * Generally, all function that return a pointer to an element in the ziplist - * will assert that this element is valid, so it can be freely used. - * Generally functions such ziplistGet assume the input pointer is already - * validated (since it's the return value of another function). */ -static inline void zipEntry(unsigned char *p, zlentry *e) { - ZIP_DECODE_PREVLEN(p, e->prevrawlensize, e->prevrawlen); - ZIP_ENTRY_ENCODING(p + e->prevrawlensize, e->encoding); - ZIP_DECODE_LENGTH(p + e->prevrawlensize, e->encoding, e->lensize, e->len); - assert(e->lensize != 0); /* check that encoding was valid. */ - e->headersize = e->prevrawlensize + e->lensize; - e->p = p; -} - -/* Fills a struct with all information about an entry. - * This function is safe to use on untrusted pointers, it'll make sure not to - * try to access memory outside the ziplist payload. - * Returns 1 if the entry is valid, and 0 otherwise. */ -static inline int zipEntrySafe(unsigned char* zl, size_t zlbytes, unsigned char *p, zlentry *e, int validate_prevlen) { - unsigned char *zlfirst = zl + ZIPLIST_HEADER_SIZE; - unsigned char *zllast = zl + zlbytes - ZIPLIST_END_SIZE; -#define OUT_OF_RANGE(p) (unlikely((p) < zlfirst || (p) > zllast)) - - /* If there's no possibility for the header to reach outside the ziplist, - * take the fast path. (max lensize and prevrawlensize are both 5 bytes) */ - if (p >= zlfirst && p + 10 < zllast) { - ZIP_DECODE_PREVLEN(p, e->prevrawlensize, e->prevrawlen); - ZIP_ENTRY_ENCODING(p + e->prevrawlensize, e->encoding); - ZIP_DECODE_LENGTH(p + e->prevrawlensize, e->encoding, e->lensize, e->len); - e->headersize = e->prevrawlensize + e->lensize; - e->p = p; - /* We didn't call ZIP_ASSERT_ENCODING, so we check lensize was set to 0. */ - if (unlikely(e->lensize == 0)) - return 0; - /* Make sure the entry doesn't reach outside the edge of the ziplist */ - if (OUT_OF_RANGE(p + e->headersize + e->len)) - return 0; - /* Make sure prevlen doesn't reach outside the edge of the ziplist */ - if (validate_prevlen && OUT_OF_RANGE(p - e->prevrawlen)) - return 0; - return 1; - } - - /* Make sure the pointer doesn't reach outside the edge of the ziplist */ - if (OUT_OF_RANGE(p)) - return 0; - - /* Make sure the encoded prevlen header doesn't reach outside the allocation */ - ZIP_DECODE_PREVLENSIZE(p, e->prevrawlensize); - if (OUT_OF_RANGE(p + e->prevrawlensize)) - return 0; - - /* Make sure encoded entry header is valid. */ - ZIP_ENTRY_ENCODING(p + e->prevrawlensize, e->encoding); - e->lensize = zipEncodingLenSize(e->encoding); - if (unlikely(e->lensize == ZIP_ENCODING_SIZE_INVALID)) - return 0; - - /* Make sure the encoded entry header doesn't reach outside the allocation */ - if (OUT_OF_RANGE(p + e->prevrawlensize + e->lensize)) - return 0; - - /* Decode the prevlen and entry len headers. */ - ZIP_DECODE_PREVLEN(p, e->prevrawlensize, e->prevrawlen); - ZIP_DECODE_LENGTH(p + e->prevrawlensize, e->encoding, e->lensize, e->len); - e->headersize = e->prevrawlensize + e->lensize; - - /* Make sure the entry doesn't reach outside the edge of the ziplist */ - if (OUT_OF_RANGE(p + e->headersize + e->len)) - return 0; - - /* Make sure prevlen doesn't reach outside the edge of the ziplist */ - if (validate_prevlen && OUT_OF_RANGE(p - e->prevrawlen)) - return 0; - - e->p = p; - return 1; -#undef OUT_OF_RANGE -} - -/* Return the total number of bytes used by the entry pointed to by 'p'. */ -static inline unsigned int zipRawEntryLengthSafe(unsigned char* zl, size_t zlbytes, unsigned char *p) { - zlentry e; - assert(zipEntrySafe(zl, zlbytes, p, &e, 0)); - return e.headersize + e.len; -} - -/* Return the total number of bytes used by the entry pointed to by 'p'. */ -static inline unsigned int zipRawEntryLength(unsigned char *p) { - zlentry e; - zipEntry(p, &e); - return e.headersize + e.len; -} - -/* Validate that the entry doesn't reach outside the ziplist allocation. */ -static inline void zipAssertValidEntry(unsigned char* zl, size_t zlbytes, unsigned char *p) { - zlentry e; - assert(zipEntrySafe(zl, zlbytes, p, &e, 1)); -} - -/* Create a new empty ziplist. */ -unsigned char *ziplistNew(void) { - unsigned int bytes = ZIPLIST_HEADER_SIZE+ZIPLIST_END_SIZE; - unsigned char *zl = zmalloc(bytes); - ZIPLIST_BYTES(zl) = intrev32ifbe(bytes); - ZIPLIST_TAIL_OFFSET(zl) = intrev32ifbe(ZIPLIST_HEADER_SIZE); - ZIPLIST_LENGTH(zl) = 0; - zl[bytes-1] = ZIP_END; - return zl; -} - -/* Resize the ziplist. */ -unsigned char *ziplistResize(unsigned char *zl, size_t len) { - assert(len < UINT32_MAX); - zl = zrealloc(zl,len); - ZIPLIST_BYTES(zl) = intrev32ifbe(len); - zl[len-1] = ZIP_END; - return zl; -} - -/* When an entry is inserted, we need to set the prevlen field of the next - * entry to equal the length of the inserted entry. It can occur that this - * length cannot be encoded in 1 byte and the next entry needs to be grow - * a bit larger to hold the 5-byte encoded prevlen. This can be done for free, - * because this only happens when an entry is already being inserted (which - * causes a realloc and memmove). However, encoding the prevlen may require - * that this entry is grown as well. This effect may cascade throughout - * the ziplist when there are consecutive entries with a size close to - * ZIP_BIG_PREVLEN, so we need to check that the prevlen can be encoded in - * every consecutive entry. - * - * Note that this effect can also happen in reverse, where the bytes required - * to encode the prevlen field can shrink. This effect is deliberately ignored, - * because it can cause a "flapping" effect where a chain prevlen fields is - * first grown and then shrunk again after consecutive inserts. Rather, the - * field is allowed to stay larger than necessary, because a large prevlen - * field implies the ziplist is holding large entries anyway. - * - * The pointer "p" points to the first entry that does NOT need to be - * updated, i.e. consecutive fields MAY need an update. */ -unsigned char *__ziplistCascadeUpdate(unsigned char *zl, unsigned char *p) { - zlentry cur; - size_t prevlen, prevlensize, prevoffset; /* Informat of the last changed entry. */ - size_t firstentrylen; /* Used to handle insert at head. */ - size_t rawlen, curlen = intrev32ifbe(ZIPLIST_BYTES(zl)); - size_t extra = 0, cnt = 0, offset; - size_t delta = 4; /* Extra bytes needed to update a entry's prevlen (5-1). */ - unsigned char *tail = zl + intrev32ifbe(ZIPLIST_TAIL_OFFSET(zl)); - - /* Empty ziplist */ - if (p[0] == ZIP_END) return zl; - - zipEntry(p, &cur); /* no need for "safe" variant since the input pointer was validated by the function that returned it. */ - firstentrylen = prevlen = cur.headersize + cur.len; - prevlensize = zipStorePrevEntryLength(NULL, prevlen); - prevoffset = p - zl; - p += prevlen; - - /* Iterate ziplist to find out how many extra bytes do we need to update it. */ - while (p[0] != ZIP_END) { - assert(zipEntrySafe(zl, curlen, p, &cur, 0)); - - /* Abort when "prevlen" has not changed. */ - if (cur.prevrawlen == prevlen) break; - - /* Abort when entry's "prevlensize" is big enough. */ - if (cur.prevrawlensize >= prevlensize) { - if (cur.prevrawlensize == prevlensize) { - zipStorePrevEntryLength(p, prevlen); - } else { - /* This would result in shrinking, which we want to avoid. - * So, set "prevlen" in the available bytes. */ - zipStorePrevEntryLengthLarge(p, prevlen); - } - break; - } - - /* cur.prevrawlen means cur is the former head entry. */ - assert(cur.prevrawlen == 0 || cur.prevrawlen + delta == prevlen); - - /* Update prev entry's info and advance the cursor. */ - rawlen = cur.headersize + cur.len; - prevlen = rawlen + delta; - prevlensize = zipStorePrevEntryLength(NULL, prevlen); - prevoffset = p - zl; - p += rawlen; - extra += delta; - cnt++; - } - - /* Extra bytes is zero all update has been done(or no need to update). */ - if (extra == 0) return zl; - - /* Update tail offset after loop. */ - if (tail == zl + prevoffset) { - /* When the last entry we need to update is also the tail, update tail offset - * unless this is the only entry that was updated (so the tail offset didn't change). */ - if (extra - delta != 0) { - ZIPLIST_TAIL_OFFSET(zl) = - intrev32ifbe(intrev32ifbe(ZIPLIST_TAIL_OFFSET(zl))+extra-delta); - } - } else { - /* Update the tail offset in cases where the last entry we updated is not the tail. */ - ZIPLIST_TAIL_OFFSET(zl) = - intrev32ifbe(intrev32ifbe(ZIPLIST_TAIL_OFFSET(zl))+extra); - } - - /* Now "p" points at the first unchanged byte in original ziplist, - * move data after that to new ziplist. */ - offset = p - zl; - zl = ziplistResize(zl, curlen + extra); - p = zl + offset; - memmove(p + extra, p, curlen - offset - 1); - p += extra; - - /* Iterate all entries that need to be updated tail to head. */ - while (cnt) { - zipEntry(zl + prevoffset, &cur); /* no need for "safe" variant since we already iterated on all these entries above. */ - rawlen = cur.headersize + cur.len; - /* Move entry to tail and reset prevlen. */ - memmove(p - (rawlen - cur.prevrawlensize), - zl + prevoffset + cur.prevrawlensize, - rawlen - cur.prevrawlensize); - p -= (rawlen + delta); - if (cur.prevrawlen == 0) { - /* "cur" is the previous head entry, update its prevlen with firstentrylen. */ - zipStorePrevEntryLength(p, firstentrylen); - } else { - /* An entry's prevlen can only increment 4 bytes. */ - zipStorePrevEntryLength(p, cur.prevrawlen+delta); - } - /* Forward to previous entry. */ - prevoffset -= cur.prevrawlen; - cnt--; - } - return zl; -} - -/* Delete "num" entries, starting at "p". Returns pointer to the ziplist. */ -unsigned char *__ziplistDelete(unsigned char *zl, unsigned char *p, unsigned int num) { - unsigned int i, totlen, deleted = 0; - size_t offset; - int nextdiff = 0; - zlentry first, tail; - size_t zlbytes = intrev32ifbe(ZIPLIST_BYTES(zl)); - - zipEntry(p, &first); /* no need for "safe" variant since the input pointer was validated by the function that returned it. */ - for (i = 0; p[0] != ZIP_END && i < num; i++) { - p += zipRawEntryLengthSafe(zl, zlbytes, p); - deleted++; - } - - assert(p >= first.p); - totlen = p-first.p; /* Bytes taken by the element(s) to delete. */ - if (totlen > 0) { - uint32_t set_tail; - if (p[0] != ZIP_END) { - /* Storing `prevrawlen` in this entry may increase or decrease the - * number of bytes required compare to the current `prevrawlen`. - * There always is room to store this, because it was previously - * stored by an entry that is now being deleted. */ - nextdiff = zipPrevLenByteDiff(p,first.prevrawlen); - - /* Note that there is always space when p jumps backward: if - * the new previous entry is large, one of the deleted elements - * had a 5 bytes prevlen header, so there is for sure at least - * 5 bytes free and we need just 4. */ - p -= nextdiff; - assert(p >= first.p && p<zl+zlbytes-1); - zipStorePrevEntryLength(p,first.prevrawlen); - - /* Update offset for tail */ - set_tail = intrev32ifbe(ZIPLIST_TAIL_OFFSET(zl))-totlen; - - /* When the tail contains more than one entry, we need to take - * "nextdiff" in account as well. Otherwise, a change in the - * size of prevlen doesn't have an effect on the *tail* offset. */ - assert(zipEntrySafe(zl, zlbytes, p, &tail, 1)); - if (p[tail.headersize+tail.len] != ZIP_END) { - set_tail = set_tail + nextdiff; - } - - /* Move tail to the front of the ziplist */ - /* since we asserted that p >= first.p. we know totlen >= 0, - * so we know that p > first.p and this is guaranteed not to reach - * beyond the allocation, even if the entries lens are corrupted. */ - size_t bytes_to_move = zlbytes-(p-zl)-1; - memmove(first.p,p,bytes_to_move); - } else { - /* The entire tail was deleted. No need to move memory. */ - set_tail = (first.p-zl)-first.prevrawlen; - } - - /* Resize the ziplist */ - offset = first.p-zl; - zlbytes -= totlen - nextdiff; - zl = ziplistResize(zl, zlbytes); - p = zl+offset; - - /* Update record count */ - ZIPLIST_INCR_LENGTH(zl,-deleted); - - /* Set the tail offset computed above */ - assert(set_tail <= zlbytes - ZIPLIST_END_SIZE); - ZIPLIST_TAIL_OFFSET(zl) = intrev32ifbe(set_tail); - - /* When nextdiff != 0, the raw length of the next entry has changed, so - * we need to cascade the update throughout the ziplist */ - if (nextdiff != 0) - zl = __ziplistCascadeUpdate(zl,p); - } - return zl; -} - -/* Insert item at "p". */ -unsigned char *__ziplistInsert(unsigned char *zl, unsigned char *p, unsigned char *s, unsigned int slen) { - size_t curlen = intrev32ifbe(ZIPLIST_BYTES(zl)), reqlen, newlen; - unsigned int prevlensize, prevlen = 0; - size_t offset; - int nextdiff = 0; - unsigned char encoding = 0; - long long value = 123456789; /* initialized to avoid warning. Using a value - that is easy to see if for some reason - we use it uninitialized. */ - zlentry tail; - - /* Find out prevlen for the entry that is inserted. */ - if (p[0] != ZIP_END) { - ZIP_DECODE_PREVLEN(p, prevlensize, prevlen); - } else { - unsigned char *ptail = ZIPLIST_ENTRY_TAIL(zl); - if (ptail[0] != ZIP_END) { - prevlen = zipRawEntryLengthSafe(zl, curlen, ptail); - } - } - - /* See if the entry can be encoded */ - if (zipTryEncoding(s,slen,&value,&encoding)) { - /* 'encoding' is set to the appropriate integer encoding */ - reqlen = zipIntSize(encoding); - } else { - /* 'encoding' is untouched, however zipStoreEntryEncoding will use the - * string length to figure out how to encode it. */ - reqlen = slen; - } - /* We need space for both the length of the previous entry and - * the length of the payload. */ - reqlen += zipStorePrevEntryLength(NULL,prevlen); - reqlen += zipStoreEntryEncoding(NULL,encoding,slen); - - /* When the insert position is not equal to the tail, we need to - * make sure that the next entry can hold this entry's length in - * its prevlen field. */ - int forcelarge = 0; - nextdiff = (p[0] != ZIP_END) ? zipPrevLenByteDiff(p,reqlen) : 0; - if (nextdiff == -4 && reqlen < 4) { - nextdiff = 0; - forcelarge = 1; - } - - /* Store offset because a realloc may change the address of zl. */ - offset = p-zl; - newlen = curlen+reqlen+nextdiff; - zl = ziplistResize(zl,newlen); - p = zl+offset; - - /* Apply memory move when necessary and update tail offset. */ - if (p[0] != ZIP_END) { - /* Subtract one because of the ZIP_END bytes */ - memmove(p+reqlen,p-nextdiff,curlen-offset-1+nextdiff); - - /* Encode this entry's raw length in the next entry. */ - if (forcelarge) - zipStorePrevEntryLengthLarge(p+reqlen,reqlen); - else - zipStorePrevEntryLength(p+reqlen,reqlen); - - /* Update offset for tail */ - ZIPLIST_TAIL_OFFSET(zl) = - intrev32ifbe(intrev32ifbe(ZIPLIST_TAIL_OFFSET(zl))+reqlen); - - /* When the tail contains more than one entry, we need to take - * "nextdiff" in account as well. Otherwise, a change in the - * size of prevlen doesn't have an effect on the *tail* offset. */ - assert(zipEntrySafe(zl, newlen, p+reqlen, &tail, 1)); - if (p[reqlen+tail.headersize+tail.len] != ZIP_END) { - ZIPLIST_TAIL_OFFSET(zl) = - intrev32ifbe(intrev32ifbe(ZIPLIST_TAIL_OFFSET(zl))+nextdiff); - } - } else { - /* This element will be the new tail. */ - ZIPLIST_TAIL_OFFSET(zl) = intrev32ifbe(p-zl); - } - - /* When nextdiff != 0, the raw length of the next entry has changed, so - * we need to cascade the update throughout the ziplist */ - if (nextdiff != 0) { - offset = p-zl; - zl = __ziplistCascadeUpdate(zl,p+reqlen); - p = zl+offset; - } - - /* Write the entry */ - p += zipStorePrevEntryLength(p,prevlen); - p += zipStoreEntryEncoding(p,encoding,slen); - if (ZIP_IS_STR(encoding)) { - memcpy(p,s,slen); - } else { - zipSaveInteger(p,value,encoding); - } - ZIPLIST_INCR_LENGTH(zl,1); - return zl; -} - -/* Merge ziplists 'first' and 'second' by appending 'second' to 'first'. - * - * NOTE: The larger ziplist is reallocated to contain the new merged ziplist. - * Either 'first' or 'second' can be used for the result. The parameter not - * used will be free'd and set to NULL. - * - * After calling this function, the input parameters are no longer valid since - * they are changed and free'd in-place. - * - * The result ziplist is the contents of 'first' followed by 'second'. - * - * On failure: returns NULL if the merge is impossible. - * On success: returns the merged ziplist (which is expanded version of either - * 'first' or 'second', also frees the other unused input ziplist, and sets the - * input ziplist argument equal to newly reallocated ziplist return value. */ -unsigned char *ziplistMerge(unsigned char **first, unsigned char **second) { - /* If any params are null, we can't merge, so NULL. */ - if (first == NULL || *first == NULL || second == NULL || *second == NULL) - return NULL; - - /* Can't merge same list into itself. */ - if (*first == *second) - return NULL; - - size_t first_bytes = intrev32ifbe(ZIPLIST_BYTES(*first)); - size_t first_len = intrev16ifbe(ZIPLIST_LENGTH(*first)); - - size_t second_bytes = intrev32ifbe(ZIPLIST_BYTES(*second)); - size_t second_len = intrev16ifbe(ZIPLIST_LENGTH(*second)); - - int append; - unsigned char *source, *target; - size_t target_bytes, source_bytes; - /* Pick the largest ziplist so we can resize easily in-place. - * We must also track if we are now appending or prepending to - * the target ziplist. */ - if (first_len >= second_len) { - /* retain first, append second to first. */ - target = *first; - target_bytes = first_bytes; - source = *second; - source_bytes = second_bytes; - append = 1; - } else { - /* else, retain second, prepend first to second. */ - target = *second; - target_bytes = second_bytes; - source = *first; - source_bytes = first_bytes; - append = 0; - } - - /* Calculate final bytes (subtract one pair of metadata) */ - size_t zlbytes = first_bytes + second_bytes - - ZIPLIST_HEADER_SIZE - ZIPLIST_END_SIZE; - size_t zllength = first_len + second_len; - - /* Combined zl length should be limited within UINT16_MAX */ - zllength = zllength < UINT16_MAX ? zllength : UINT16_MAX; - - /* larger values can't be stored into ZIPLIST_BYTES */ - assert(zlbytes < UINT32_MAX); - - /* Save offset positions before we start ripping memory apart. */ - size_t first_offset = intrev32ifbe(ZIPLIST_TAIL_OFFSET(*first)); - size_t second_offset = intrev32ifbe(ZIPLIST_TAIL_OFFSET(*second)); - - /* Extend target to new zlbytes then append or prepend source. */ - target = zrealloc(target, zlbytes); - if (append) { - /* append == appending to target */ - /* Copy source after target (copying over original [END]): - * [TARGET - END, SOURCE - HEADER] */ - memcpy(target + target_bytes - ZIPLIST_END_SIZE, - source + ZIPLIST_HEADER_SIZE, - source_bytes - ZIPLIST_HEADER_SIZE); - } else { - /* !append == prepending to target */ - /* Move target *contents* exactly size of (source - [END]), - * then copy source into vacated space (source - [END]): - * [SOURCE - END, TARGET - HEADER] */ - memmove(target + source_bytes - ZIPLIST_END_SIZE, - target + ZIPLIST_HEADER_SIZE, - target_bytes - ZIPLIST_HEADER_SIZE); - memcpy(target, source, source_bytes - ZIPLIST_END_SIZE); - } - - /* Update header metadata. */ - ZIPLIST_BYTES(target) = intrev32ifbe(zlbytes); - ZIPLIST_LENGTH(target) = intrev16ifbe(zllength); - /* New tail offset is: - * + N bytes of first ziplist - * - 1 byte for [END] of first ziplist - * + M bytes for the offset of the original tail of the second ziplist - * - J bytes for HEADER because second_offset keeps no header. */ - ZIPLIST_TAIL_OFFSET(target) = intrev32ifbe( - (first_bytes - ZIPLIST_END_SIZE) + - (second_offset - ZIPLIST_HEADER_SIZE)); - - /* __ziplistCascadeUpdate just fixes the prev length values until it finds a - * correct prev length value (then it assumes the rest of the list is okay). - * We tell CascadeUpdate to start at the first ziplist's tail element to fix - * the merge seam. */ - target = __ziplistCascadeUpdate(target, target+first_offset); - - /* Now free and NULL out what we didn't realloc */ - if (append) { - zfree(*second); - *second = NULL; - *first = target; - } else { - zfree(*first); - *first = NULL; - *second = target; - } - return target; -} - -unsigned char *ziplistPush(unsigned char *zl, unsigned char *s, unsigned int slen, int where) { - unsigned char *p; - p = (where == ZIPLIST_HEAD) ? ZIPLIST_ENTRY_HEAD(zl) : ZIPLIST_ENTRY_END(zl); - return __ziplistInsert(zl,p,s,slen); -} - -/* Returns an offset to use for iterating with ziplistNext. When the given - * index is negative, the list is traversed back to front. When the list - * doesn't contain an element at the provided index, NULL is returned. */ -unsigned char *ziplistIndex(unsigned char *zl, int index) { - unsigned char *p; - unsigned int prevlensize, prevlen = 0; - size_t zlbytes = intrev32ifbe(ZIPLIST_BYTES(zl)); - if (index < 0) { - index = (-index)-1; - p = ZIPLIST_ENTRY_TAIL(zl); - if (p[0] != ZIP_END) { - /* No need for "safe" check: when going backwards, we know the header - * we're parsing is in the range, we just need to assert (below) that - * the size we take doesn't cause p to go outside the allocation. */ - ZIP_DECODE_PREVLENSIZE(p, prevlensize); - assert(p + prevlensize < zl + zlbytes - ZIPLIST_END_SIZE); - ZIP_DECODE_PREVLEN(p, prevlensize, prevlen); - while (prevlen > 0 && index--) { - p -= prevlen; - assert(p >= zl + ZIPLIST_HEADER_SIZE && p < zl + zlbytes - ZIPLIST_END_SIZE); - ZIP_DECODE_PREVLEN(p, prevlensize, prevlen); - } - } - } else { - p = ZIPLIST_ENTRY_HEAD(zl); - while (index--) { - /* Use the "safe" length: When we go forward, we need to be careful - * not to decode an entry header if it's past the ziplist allocation. */ - p += zipRawEntryLengthSafe(zl, zlbytes, p); - if (p[0] == ZIP_END) - break; - } - } - if (p[0] == ZIP_END || index > 0) - return NULL; - zipAssertValidEntry(zl, zlbytes, p); - return p; -} - -/* Return pointer to next entry in ziplist. - * - * zl is the pointer to the ziplist - * p is the pointer to the current element - * - * The element after 'p' is returned, otherwise NULL if we are at the end. */ -unsigned char *ziplistNext(unsigned char *zl, unsigned char *p) { - ((void) zl); - size_t zlbytes = intrev32ifbe(ZIPLIST_BYTES(zl)); - - /* "p" could be equal to ZIP_END, caused by ziplistDelete, - * and we should return NULL. Otherwise, we should return NULL - * when the *next* element is ZIP_END (there is no next entry). */ - if (p[0] == ZIP_END) { - return NULL; - } - - p += zipRawEntryLength(p); - if (p[0] == ZIP_END) { - return NULL; - } - - zipAssertValidEntry(zl, zlbytes, p); - return p; -} - -/* Return pointer to previous entry in ziplist. */ -unsigned char *ziplistPrev(unsigned char *zl, unsigned char *p) { - unsigned int prevlensize, prevlen = 0; - - /* Iterating backwards from ZIP_END should return the tail. When "p" is - * equal to the first element of the list, we're already at the head, - * and should return NULL. */ - if (p[0] == ZIP_END) { - p = ZIPLIST_ENTRY_TAIL(zl); - return (p[0] == ZIP_END) ? NULL : p; - } else if (p == ZIPLIST_ENTRY_HEAD(zl)) { - return NULL; - } else { - ZIP_DECODE_PREVLEN(p, prevlensize, prevlen); - assert(prevlen > 0); - p-=prevlen; - size_t zlbytes = intrev32ifbe(ZIPLIST_BYTES(zl)); - zipAssertValidEntry(zl, zlbytes, p); - return p; - } -} - -/* Get entry pointed to by 'p' and store in either '*sstr' or 'sval' depending - * on the encoding of the entry. '*sstr' is always set to NULL to be able - * to find out whether the string pointer or the integer value was set. - * Return 0 if 'p' points to the end of the ziplist, 1 otherwise. */ -unsigned int ziplistGet(unsigned char *p, unsigned char **sstr, unsigned int *slen, long long *sval) { - zlentry entry; - if (p == NULL || p[0] == ZIP_END) return 0; - if (sstr) *sstr = NULL; - - zipEntry(p, &entry); /* no need for "safe" variant since the input pointer was validated by the function that returned it. */ - if (ZIP_IS_STR(entry.encoding)) { - if (sstr) { - *slen = entry.len; - *sstr = p+entry.headersize; - } - } else { - if (sval) { - *sval = zipLoadInteger(p+entry.headersize,entry.encoding); - } - } - return 1; -} - -/* Insert an entry at "p". */ -unsigned char *ziplistInsert(unsigned char *zl, unsigned char *p, unsigned char *s, unsigned int slen) { - return __ziplistInsert(zl,p,s,slen); -} - -/* Delete a single entry from the ziplist, pointed to by *p. - * Also update *p in place, to be able to iterate over the - * ziplist, while deleting entries. */ -unsigned char *ziplistDelete(unsigned char *zl, unsigned char **p) { - size_t offset = *p-zl; - zl = __ziplistDelete(zl,*p,1); - - /* Store pointer to current element in p, because ziplistDelete will - * do a realloc which might result in a different "zl"-pointer. - * When the delete direction is back to front, we might delete the last - * entry and end up with "p" pointing to ZIP_END, so check this. */ - *p = zl+offset; - return zl; -} - -/* Delete a range of entries from the ziplist. */ -unsigned char *ziplistDeleteRange(unsigned char *zl, int index, unsigned int num) { - unsigned char *p = ziplistIndex(zl,index); - return (p == NULL) ? zl : __ziplistDelete(zl,p,num); -} - -/* Replaces the entry at p. This is equivalent to a delete and an insert, - * but avoids some overhead when replacing a value of the same size. */ -unsigned char *ziplistReplace(unsigned char *zl, unsigned char *p, unsigned char *s, unsigned int slen) { - - /* get metadata of the current entry */ - zlentry entry; - zipEntry(p, &entry); - - /* compute length of entry to store, excluding prevlen */ - unsigned int reqlen; - unsigned char encoding = 0; - long long value = 123456789; /* initialized to avoid warning. */ - if (zipTryEncoding(s,slen,&value,&encoding)) { - reqlen = zipIntSize(encoding); /* encoding is set */ - } else { - reqlen = slen; /* encoding == 0 */ - } - reqlen += zipStoreEntryEncoding(NULL,encoding,slen); - - if (reqlen == entry.lensize + entry.len) { - /* Simply overwrite the element. */ - p += entry.prevrawlensize; - p += zipStoreEntryEncoding(p,encoding,slen); - if (ZIP_IS_STR(encoding)) { - memcpy(p,s,slen); - } else { - zipSaveInteger(p,value,encoding); - } - } else { - /* Fallback. */ - zl = ziplistDelete(zl,&p); - zl = ziplistInsert(zl,p,s,slen); - } - return zl; -} - -/* Compare entry pointer to by 'p' with 'sstr' of length 'slen'. */ -/* Return 1 if equal. */ -unsigned int ziplistCompare(unsigned char *p, unsigned char *sstr, unsigned int slen) { - zlentry entry; - unsigned char sencoding; - long long zval, sval; - if (p[0] == ZIP_END) return 0; - - zipEntry(p, &entry); /* no need for "safe" variant since the input pointer was validated by the function that returned it. */ - if (ZIP_IS_STR(entry.encoding)) { - /* Raw compare */ - if (entry.len == slen) { - return memcmp(p+entry.headersize,sstr,slen) == 0; - } else { - return 0; - } - } else { - /* Try to compare encoded values. Don't compare encoding because - * different implementations may encoded integers differently. */ - if (zipTryEncoding(sstr,slen,&sval,&sencoding)) { - zval = zipLoadInteger(p+entry.headersize,entry.encoding); - return zval == sval; - } - } - return 0; -} - -/* Find pointer to the entry equal to the specified entry. Skip 'skip' entries - * between every comparison. Returns NULL when the field could not be found. */ -unsigned char *ziplistFind(unsigned char *zl, unsigned char *p, unsigned char *vstr, unsigned int vlen, unsigned int skip) { - int skipcnt = 0; - unsigned char vencoding = 0; - long long vll = 0; - size_t zlbytes = ziplistBlobLen(zl); - - while (p[0] != ZIP_END) { - struct zlentry e; - unsigned char *q; - - assert(zipEntrySafe(zl, zlbytes, p, &e, 1)); - q = p + e.prevrawlensize + e.lensize; - - if (skipcnt == 0) { - /* Compare current entry with specified entry */ - if (ZIP_IS_STR(e.encoding)) { - if (e.len == vlen && memcmp(q, vstr, vlen) == 0) { - return p; - } - } else { - /* Find out if the searched field can be encoded. Note that - * we do it only the first time, once done vencoding is set - * to non-zero and vll is set to the integer value. */ - if (vencoding == 0) { - if (!zipTryEncoding(vstr, vlen, &vll, &vencoding)) { - /* If the entry can't be encoded we set it to - * UCHAR_MAX so that we don't retry again the next - * time. */ - vencoding = UCHAR_MAX; - } - /* Must be non-zero by now */ - assert(vencoding); - } - - /* Compare current entry with specified entry, do it only - * if vencoding != UCHAR_MAX because if there is no encoding - * possible for the field it can't be a valid integer. */ - if (vencoding != UCHAR_MAX) { - long long ll = zipLoadInteger(q, e.encoding); - if (ll == vll) { - return p; - } - } - } - - /* Reset skip count */ - skipcnt = skip; - } else { - /* Skip entry */ - skipcnt--; - } - - /* Move to next entry */ - p = q + e.len; - } - - return NULL; -} - -/* Return length of ziplist. */ -unsigned int ziplistLen(unsigned char *zl) { - unsigned int len = 0; - if (intrev16ifbe(ZIPLIST_LENGTH(zl)) < UINT16_MAX) { - len = intrev16ifbe(ZIPLIST_LENGTH(zl)); - } else { - unsigned char *p = zl+ZIPLIST_HEADER_SIZE; - size_t zlbytes = intrev32ifbe(ZIPLIST_BYTES(zl)); - while (*p != ZIP_END) { - p += zipRawEntryLengthSafe(zl, zlbytes, p); - len++; - } - - /* Re-store length if small enough */ - if (len < UINT16_MAX) ZIPLIST_LENGTH(zl) = intrev16ifbe(len); - } - return len; -} - -/* Return ziplist blob size in bytes. */ -size_t ziplistBlobLen(unsigned char *zl) { - return intrev32ifbe(ZIPLIST_BYTES(zl)); -} - -void ziplistRepr(unsigned char *zl) { - unsigned char *p; - int index = 0; - zlentry entry; - size_t zlbytes = ziplistBlobLen(zl); - - printf( - "{total bytes %u} " - "{num entries %u}\n" - "{tail offset %u}\n", - intrev32ifbe(ZIPLIST_BYTES(zl)), - intrev16ifbe(ZIPLIST_LENGTH(zl)), - intrev32ifbe(ZIPLIST_TAIL_OFFSET(zl))); - p = ZIPLIST_ENTRY_HEAD(zl); - while(*p != ZIP_END) { - assert(zipEntrySafe(zl, zlbytes, p, &entry, 1)); - printf( - "{\n" - "\taddr 0x%08lx,\n" - "\tindex %2d,\n" - "\toffset %5lu,\n" - "\thdr+entry len: %5u,\n" - "\thdr len%2u,\n" - "\tprevrawlen: %5u,\n" - "\tprevrawlensize: %2u,\n" - "\tpayload %5u\n", - (long unsigned)p, - index, - (unsigned long) (p-zl), - entry.headersize+entry.len, - entry.headersize, - entry.prevrawlen, - entry.prevrawlensize, - entry.len); - printf("\tbytes: "); - for (unsigned int i = 0; i < entry.headersize+entry.len; i++) { - printf("%02x|",p[i]); - } - printf("\n"); - p += entry.headersize; - if (ZIP_IS_STR(entry.encoding)) { - printf("\t[str]"); - if (entry.len > 40) { - if (fwrite(p,40,1,stdout) == 0) perror("fwrite"); - printf("..."); - } else { - if (entry.len && - fwrite(p,entry.len,1,stdout) == 0) perror("fwrite"); - } - } else { - printf("\t[int]%lld", (long long) zipLoadInteger(p,entry.encoding)); - } - printf("\n}\n"); - p += entry.len; - index++; - } - printf("{end}\n\n"); -} - -/* Validate the integrity of the data structure. - * when `deep` is 0, only the integrity of the header is validated. - * when `deep` is 1, we scan all the entries one by one. */ -int ziplistValidateIntegrity(unsigned char *zl, size_t size, int deep, - ziplistValidateEntryCB entry_cb, void *cb_userdata) { - /* check that we can actually read the header. (and ZIP_END) */ - if (size < ZIPLIST_HEADER_SIZE + ZIPLIST_END_SIZE) - return 0; - - /* check that the encoded size in the header must match the allocated size. */ - size_t bytes = intrev32ifbe(ZIPLIST_BYTES(zl)); - if (bytes != size) - return 0; - - /* the last byte must be the terminator. */ - if (zl[size - ZIPLIST_END_SIZE] != ZIP_END) - return 0; - - /* make sure the tail offset isn't reaching outside the allocation. */ - if (intrev32ifbe(ZIPLIST_TAIL_OFFSET(zl)) > size - ZIPLIST_END_SIZE) - return 0; - - if (!deep) - return 1; - - unsigned int count = 0; - unsigned int header_count = intrev16ifbe(ZIPLIST_LENGTH(zl)); - unsigned char *p = ZIPLIST_ENTRY_HEAD(zl); - unsigned char *prev = NULL; - size_t prev_raw_size = 0; - while(*p != ZIP_END) { - struct zlentry e; - /* Decode the entry headers and fail if invalid or reaches outside the allocation */ - if (!zipEntrySafe(zl, size, p, &e, 1)) - return 0; - - /* Make sure the record stating the prev entry size is correct. */ - if (e.prevrawlen != prev_raw_size) - return 0; - - /* Optionally let the caller validate the entry too. */ - if (entry_cb && !entry_cb(p, header_count, cb_userdata)) - return 0; - - /* Move to the next entry */ - prev_raw_size = e.headersize + e.len; - prev = p; - p += e.headersize + e.len; - count++; - } - - /* Make sure 'p' really does point to the end of the ziplist. */ - if (p != zl + bytes - ZIPLIST_END_SIZE) - return 0; - - /* Make sure the <zltail> entry really do point to the start of the last entry. */ - if (prev != NULL && prev != ZIPLIST_ENTRY_TAIL(zl)) - return 0; - - /* Check that the count in the header is correct */ - if (header_count != UINT16_MAX && count != header_count) - return 0; - - return 1; -} - -/* Randomly select a pair of key and value. - * total_count is a pre-computed length/2 of the ziplist (to avoid calls to ziplistLen) - * 'key' and 'val' are used to store the result key value pair. - * 'val' can be NULL if the value is not needed. */ -void ziplistRandomPair(unsigned char *zl, unsigned long total_count, ziplistEntry *key, ziplistEntry *val) { - int ret; - unsigned char *p; - - /* Avoid div by zero on corrupt ziplist */ - assert(total_count); - - /* Generate even numbers, because ziplist saved K-V pair */ - int r = (rand() % total_count) * 2; - p = ziplistIndex(zl, r); - ret = ziplistGet(p, &key->sval, &key->slen, &key->lval); - assert(ret != 0); - - if (!val) - return; - p = ziplistNext(zl, p); - ret = ziplistGet(p, &val->sval, &val->slen, &val->lval); - assert(ret != 0); -} - -/* int compare for qsort */ -int uintCompare(const void *a, const void *b) { - return (*(unsigned int *) a - *(unsigned int *) b); -} - -/* Helper method to store a string from val or lval into dest */ -static inline void ziplistSaveValue(unsigned char *val, unsigned int len, long long lval, ziplistEntry *dest) { - dest->sval = val; - dest->slen = len; - dest->lval = lval; -} - -/* Randomly select count of key value pairs and store into 'keys' and - * 'vals' args. The order of the picked entries is random, and the selections - * are non-unique (repetitions are possible). - * The 'vals' arg can be NULL in which case we skip these. */ -void ziplistRandomPairs(unsigned char *zl, unsigned int count, ziplistEntry *keys, ziplistEntry *vals) { - unsigned char *p, *key, *value; - unsigned int klen = 0, vlen = 0; - long long klval = 0, vlval = 0; - - /* Notice: the index member must be first due to the use in uintCompare */ - typedef struct { - unsigned int index; - unsigned int order; - } rand_pick; - rand_pick *picks = zmalloc(sizeof(rand_pick)*count); - unsigned int total_size = ziplistLen(zl)/2; - - /* Avoid div by zero on corrupt ziplist */ - assert(total_size); - - /* create a pool of random indexes (some may be duplicate). */ - for (unsigned int i = 0; i < count; i++) { - picks[i].index = (rand() % total_size) * 2; /* Generate even indexes */ - /* keep track of the order we picked them */ - picks[i].order = i; - } - - /* sort by indexes. */ - qsort(picks, count, sizeof(rand_pick), uintCompare); - - /* fetch the elements form the ziplist into a output array respecting the original order. */ - unsigned int zipindex = picks[0].index, pickindex = 0; - p = ziplistIndex(zl, zipindex); - while (ziplistGet(p, &key, &klen, &klval) && pickindex < count) { - p = ziplistNext(zl, p); - assert(ziplistGet(p, &value, &vlen, &vlval)); - while (pickindex < count && zipindex == picks[pickindex].index) { - int storeorder = picks[pickindex].order; - ziplistSaveValue(key, klen, klval, &keys[storeorder]); - if (vals) - ziplistSaveValue(value, vlen, vlval, &vals[storeorder]); - pickindex++; - } - zipindex += 2; - p = ziplistNext(zl, p); - } - - zfree(picks); -} - -/* Randomly select count of key value pairs and store into 'keys' and - * 'vals' args. The selections are unique (no repetitions), and the order of - * the picked entries is NOT-random. - * The 'vals' arg can be NULL in which case we skip these. - * The return value is the number of items picked which can be lower than the - * requested count if the ziplist doesn't hold enough pairs. */ -unsigned int ziplistRandomPairsUnique(unsigned char *zl, unsigned int count, ziplistEntry *keys, ziplistEntry *vals) { - unsigned char *p, *key; - unsigned int klen = 0; - long long klval = 0; - unsigned int total_size = ziplistLen(zl)/2; - unsigned int index = 0; - if (count > total_size) - count = total_size; - - /* To only iterate once, every time we try to pick a member, the probability - * we pick it is the quotient of the count left we want to pick and the - * count still we haven't visited in the dict, this way, we could make every - * member be equally picked.*/ - p = ziplistIndex(zl, 0); - unsigned int picked = 0, remaining = count; - while (picked < count && p) { - double randomDouble = ((double)rand()) / RAND_MAX; - double threshold = ((double)remaining) / (total_size - index); - if (randomDouble <= threshold) { - assert(ziplistGet(p, &key, &klen, &klval)); - ziplistSaveValue(key, klen, klval, &keys[picked]); - p = ziplistNext(zl, p); - assert(p); - if (vals) { - assert(ziplistGet(p, &key, &klen, &klval)); - ziplistSaveValue(key, klen, klval, &vals[picked]); - } - remaining--; - picked++; - } else { - p = ziplistNext(zl, p); - assert(p); - } - p = ziplistNext(zl, p); - index++; - } - return picked; -} - -#ifdef REDIS_TEST -#include <sys/time.h> -#include "adlist.h" -#include "sds.h" -#include "testhelp.h" - -#define debug(f, ...) { if (DEBUG) printf(f, __VA_ARGS__); } - -static unsigned char *createList(void) { - unsigned char *zl = ziplistNew(); - zl = ziplistPush(zl, (unsigned char*)"foo", 3, ZIPLIST_TAIL); - zl = ziplistPush(zl, (unsigned char*)"quux", 4, ZIPLIST_TAIL); - zl = ziplistPush(zl, (unsigned char*)"hello", 5, ZIPLIST_HEAD); - zl = ziplistPush(zl, (unsigned char*)"1024", 4, ZIPLIST_TAIL); - return zl; -} - -static unsigned char *createIntList(void) { - unsigned char *zl = ziplistNew(); - char buf[32]; - - snprintf(buf, sizeof(buf), "100"); - zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), ZIPLIST_TAIL); - snprintf(buf, sizeof(buf), "128000"); - zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), ZIPLIST_TAIL); - snprintf(buf, sizeof(buf), "-100"); - zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), ZIPLIST_HEAD); - snprintf(buf, sizeof(buf), "4294967296"); - zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), ZIPLIST_HEAD); - snprintf(buf, sizeof(buf), "non integer"); - zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), ZIPLIST_TAIL); - snprintf(buf,sizeof(buf), "much much longer non integer"); - zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), ZIPLIST_TAIL); - return zl; -} - -static long long usec(void) { - struct timeval tv; - gettimeofday(&tv,NULL); - return (((long long)tv.tv_sec)*1000000)+tv.tv_usec; -} - -static void stress(int pos, int num, int maxsize, int dnum) { - int i,j,k; - unsigned char *zl; - char posstr[2][5] = { "HEAD", "TAIL" }; - long long start; - for (i = 0; i < maxsize; i+=dnum) { - zl = ziplistNew(); - for (j = 0; j < i; j++) { - zl = ziplistPush(zl,(unsigned char*)"quux",4,ZIPLIST_TAIL); - } - - /* Do num times a push+pop from pos */ - start = usec(); - for (k = 0; k < num; k++) { - zl = ziplistPush(zl,(unsigned char*)"quux",4,pos); - zl = ziplistDeleteRange(zl,0,1); - } - printf("List size: %8d, bytes: %8d, %dx push+pop (%s): %6lld usec\n", - i,intrev32ifbe(ZIPLIST_BYTES(zl)),num,posstr[pos],usec()-start); - zfree(zl); - } -} - -static unsigned char *pop(unsigned char *zl, int where) { - unsigned char *p, *vstr; - unsigned int vlen; - long long vlong = 0; - - p = ziplistIndex(zl,where == ZIPLIST_HEAD ? 0 : -1); - if (ziplistGet(p,&vstr,&vlen,&vlong)) { - if (where == ZIPLIST_HEAD) - printf("Pop head: "); - else - printf("Pop tail: "); - - if (vstr) { - if (vlen && fwrite(vstr,vlen,1,stdout) == 0) perror("fwrite"); - } - else { - printf("%lld", vlong); - } - - printf("\n"); - return ziplistDelete(zl,&p); - } else { - printf("ERROR: Could not pop\n"); - exit(1); - } -} - -static int randstring(char *target, unsigned int min, unsigned int max) { - int p = 0; - int len = min+rand()%(max-min+1); - int minval, maxval; - switch(rand() % 3) { - case 0: - minval = 0; - maxval = 255; - break; - case 1: - minval = 48; - maxval = 122; - break; - case 2: - minval = 48; - maxval = 52; - break; - default: - assert(NULL); - } - - while(p < len) - target[p++] = minval+rand()%(maxval-minval+1); - return len; -} - -static void verify(unsigned char *zl, zlentry *e) { - int len = ziplistLen(zl); - zlentry _e; - - ZIPLIST_ENTRY_ZERO(&_e); - - for (int i = 0; i < len; i++) { - memset(&e[i], 0, sizeof(zlentry)); - zipEntry(ziplistIndex(zl, i), &e[i]); - - memset(&_e, 0, sizeof(zlentry)); - zipEntry(ziplistIndex(zl, -len+i), &_e); - - assert(memcmp(&e[i], &_e, sizeof(zlentry)) == 0); - } -} - -static unsigned char *insertHelper(unsigned char *zl, char ch, size_t len, unsigned char *pos) { - assert(len <= ZIP_BIG_PREVLEN); - unsigned char data[ZIP_BIG_PREVLEN] = {0}; - memset(data, ch, len); - return ziplistInsert(zl, pos, data, len); -} - -static int compareHelper(unsigned char *zl, char ch, size_t len, int index) { - assert(len <= ZIP_BIG_PREVLEN); - unsigned char data[ZIP_BIG_PREVLEN] = {0}; - memset(data, ch, len); - unsigned char *p = ziplistIndex(zl, index); - assert(p != NULL); - return ziplistCompare(p, data, len); -} - -static size_t strEntryBytesSmall(size_t slen) { - return slen + zipStorePrevEntryLength(NULL, 0) + zipStoreEntryEncoding(NULL, 0, slen); -} - -static size_t strEntryBytesLarge(size_t slen) { - return slen + zipStorePrevEntryLength(NULL, ZIP_BIG_PREVLEN) + zipStoreEntryEncoding(NULL, 0, slen); -} - -/* ./redis-server test ziplist <randomseed> */ -int ziplistTest(int argc, char **argv, int flags) { - int accurate = (flags & REDIS_TEST_ACCURATE); - unsigned char *zl, *p; - unsigned char *entry; - unsigned int elen; - long long value; - int iteration; - - /* If an argument is given, use it as the random seed. */ - if (argc >= 4) - srand(atoi(argv[3])); - - zl = createIntList(); - ziplistRepr(zl); - - zfree(zl); - - zl = createList(); - ziplistRepr(zl); - - zl = pop(zl,ZIPLIST_TAIL); - ziplistRepr(zl); - - zl = pop(zl,ZIPLIST_HEAD); - ziplistRepr(zl); - - zl = pop(zl,ZIPLIST_TAIL); - ziplistRepr(zl); - - zl = pop(zl,ZIPLIST_TAIL); - ziplistRepr(zl); - - zfree(zl); - - printf("Get element at index 3:\n"); - { - zl = createList(); - p = ziplistIndex(zl, 3); - if (!ziplistGet(p, &entry, &elen, &value)) { - printf("ERROR: Could not access index 3\n"); - return 1; - } - if (entry) { - if (elen && fwrite(entry,elen,1,stdout) == 0) perror("fwrite"); - printf("\n"); - } else { - printf("%lld\n", value); - } - printf("\n"); - zfree(zl); - } - - printf("Get element at index 4 (out of range):\n"); - { - zl = createList(); - p = ziplistIndex(zl, 4); - if (p == NULL) { - printf("No entry\n"); - } else { - printf("ERROR: Out of range index should return NULL, returned offset: %ld\n", (long)(p-zl)); - return 1; - } - printf("\n"); - zfree(zl); - } - - printf("Get element at index -1 (last element):\n"); - { - zl = createList(); - p = ziplistIndex(zl, -1); - if (!ziplistGet(p, &entry, &elen, &value)) { - printf("ERROR: Could not access index -1\n"); - return 1; - } - if (entry) { - if (elen && fwrite(entry,elen,1,stdout) == 0) perror("fwrite"); - printf("\n"); - } else { - printf("%lld\n", value); - } - printf("\n"); - zfree(zl); - } - - printf("Get element at index -4 (first element):\n"); - { - zl = createList(); - p = ziplistIndex(zl, -4); - if (!ziplistGet(p, &entry, &elen, &value)) { - printf("ERROR: Could not access index -4\n"); - return 1; - } - if (entry) { - if (elen && fwrite(entry,elen,1,stdout) == 0) perror("fwrite"); - printf("\n"); - } else { - printf("%lld\n", value); - } - printf("\n"); - zfree(zl); - } - - printf("Get element at index -5 (reverse out of range):\n"); - { - zl = createList(); - p = ziplistIndex(zl, -5); - if (p == NULL) { - printf("No entry\n"); - } else { - printf("ERROR: Out of range index should return NULL, returned offset: %ld\n", (long)(p-zl)); - return 1; - } - printf("\n"); - zfree(zl); - } - - printf("Iterate list from 0 to end:\n"); - { - zl = createList(); - p = ziplistIndex(zl, 0); - while (ziplistGet(p, &entry, &elen, &value)) { - printf("Entry: "); - if (entry) { - if (elen && fwrite(entry,elen,1,stdout) == 0) perror("fwrite"); - } else { - printf("%lld", value); - } - p = ziplistNext(zl,p); - printf("\n"); - } - printf("\n"); - zfree(zl); - } - - printf("Iterate list from 1 to end:\n"); - { - zl = createList(); - p = ziplistIndex(zl, 1); - while (ziplistGet(p, &entry, &elen, &value)) { - printf("Entry: "); - if (entry) { - if (elen && fwrite(entry,elen,1,stdout) == 0) perror("fwrite"); - } else { - printf("%lld", value); - } - p = ziplistNext(zl,p); - printf("\n"); - } - printf("\n"); - zfree(zl); - } - - printf("Iterate list from 2 to end:\n"); - { - zl = createList(); - p = ziplistIndex(zl, 2); - while (ziplistGet(p, &entry, &elen, &value)) { - printf("Entry: "); - if (entry) { - if (elen && fwrite(entry,elen,1,stdout) == 0) perror("fwrite"); - } else { - printf("%lld", value); - } - p = ziplistNext(zl,p); - printf("\n"); - } - printf("\n"); - zfree(zl); - } - - printf("Iterate starting out of range:\n"); - { - zl = createList(); - p = ziplistIndex(zl, 4); - if (!ziplistGet(p, &entry, &elen, &value)) { - printf("No entry\n"); - } else { - printf("ERROR\n"); - } - printf("\n"); - zfree(zl); - } - - printf("Iterate from back to front:\n"); - { - zl = createList(); - p = ziplistIndex(zl, -1); - while (ziplistGet(p, &entry, &elen, &value)) { - printf("Entry: "); - if (entry) { - if (elen && fwrite(entry,elen,1,stdout) == 0) perror("fwrite"); - } else { - printf("%lld", value); - } - p = ziplistPrev(zl,p); - printf("\n"); - } - printf("\n"); - zfree(zl); - } - - printf("Iterate from back to front, deleting all items:\n"); - { - zl = createList(); - p = ziplistIndex(zl, -1); - while (ziplistGet(p, &entry, &elen, &value)) { - printf("Entry: "); - if (entry) { - if (elen && fwrite(entry,elen,1,stdout) == 0) perror("fwrite"); - } else { - printf("%lld", value); - } - zl = ziplistDelete(zl,&p); - p = ziplistPrev(zl,p); - printf("\n"); - } - printf("\n"); - zfree(zl); - } - - printf("Delete inclusive range 0,0:\n"); - { - zl = createList(); - zl = ziplistDeleteRange(zl, 0, 1); - ziplistRepr(zl); - zfree(zl); - } - - printf("Delete inclusive range 0,1:\n"); - { - zl = createList(); - zl = ziplistDeleteRange(zl, 0, 2); - ziplistRepr(zl); - zfree(zl); - } - - printf("Delete inclusive range 1,2:\n"); - { - zl = createList(); - zl = ziplistDeleteRange(zl, 1, 2); - ziplistRepr(zl); - zfree(zl); - } - - printf("Delete with start index out of range:\n"); - { - zl = createList(); - zl = ziplistDeleteRange(zl, 5, 1); - ziplistRepr(zl); - zfree(zl); - } - - printf("Delete with num overflow:\n"); - { - zl = createList(); - zl = ziplistDeleteRange(zl, 1, 5); - ziplistRepr(zl); - zfree(zl); - } - - printf("Delete foo while iterating:\n"); - { - zl = createList(); - p = ziplistIndex(zl,0); - while (ziplistGet(p,&entry,&elen,&value)) { - if (entry && strncmp("foo",(char*)entry,elen) == 0) { - printf("Delete foo\n"); - zl = ziplistDelete(zl,&p); - } else { - printf("Entry: "); - if (entry) { - if (elen && fwrite(entry,elen,1,stdout) == 0) - perror("fwrite"); - } else { - printf("%lld",value); - } - p = ziplistNext(zl,p); - printf("\n"); - } - } - printf("\n"); - ziplistRepr(zl); - zfree(zl); - } - - printf("Replace with same size:\n"); - { - zl = createList(); /* "hello", "foo", "quux", "1024" */ - unsigned char *orig_zl = zl; - p = ziplistIndex(zl, 0); - zl = ziplistReplace(zl, p, (unsigned char*)"zoink", 5); - p = ziplistIndex(zl, 3); - zl = ziplistReplace(zl, p, (unsigned char*)"yy", 2); - p = ziplistIndex(zl, 1); - zl = ziplistReplace(zl, p, (unsigned char*)"65536", 5); - p = ziplistIndex(zl, 0); - assert(!memcmp((char*)p, - "\x00\x05zoink" - "\x07\xf0\x00\x00\x01" /* 65536 as int24 */ - "\x05\x04quux" "\x06\x02yy" "\xff", - 23)); - assert(zl == orig_zl); /* no reallocations have happened */ - zfree(zl); - printf("SUCCESS\n\n"); - } - - printf("Replace with different size:\n"); - { - zl = createList(); /* "hello", "foo", "quux", "1024" */ - p = ziplistIndex(zl, 1); - zl = ziplistReplace(zl, p, (unsigned char*)"squirrel", 8); - p = ziplistIndex(zl, 0); - assert(!strncmp((char*)p, - "\x00\x05hello" "\x07\x08squirrel" "\x0a\x04quux" - "\x06\xc0\x00\x04" "\xff", - 28)); - zfree(zl); - printf("SUCCESS\n\n"); - } - - printf("Regression test for >255 byte strings:\n"); - { - char v1[257] = {0}, v2[257] = {0}; - memset(v1,'x',256); - memset(v2,'y',256); - zl = ziplistNew(); - zl = ziplistPush(zl,(unsigned char*)v1,strlen(v1),ZIPLIST_TAIL); - zl = ziplistPush(zl,(unsigned char*)v2,strlen(v2),ZIPLIST_TAIL); - - /* Pop values again and compare their value. */ - p = ziplistIndex(zl,0); - assert(ziplistGet(p,&entry,&elen,&value)); - assert(strncmp(v1,(char*)entry,elen) == 0); - p = ziplistIndex(zl,1); - assert(ziplistGet(p,&entry,&elen,&value)); - assert(strncmp(v2,(char*)entry,elen) == 0); - printf("SUCCESS\n\n"); - zfree(zl); - } - - printf("Regression test deleting next to last entries:\n"); - { - char v[3][257] = {{0}}; - zlentry e[3] = {{.prevrawlensize = 0, .prevrawlen = 0, .lensize = 0, - .len = 0, .headersize = 0, .encoding = 0, .p = NULL}}; - size_t i; - - for (i = 0; i < (sizeof(v)/sizeof(v[0])); i++) { - memset(v[i], 'a' + i, sizeof(v[0])); - } - - v[0][256] = '\0'; - v[1][ 1] = '\0'; - v[2][256] = '\0'; - - zl = ziplistNew(); - for (i = 0; i < (sizeof(v)/sizeof(v[0])); i++) { - zl = ziplistPush(zl, (unsigned char *) v[i], strlen(v[i]), ZIPLIST_TAIL); - } - - verify(zl, e); - - assert(e[0].prevrawlensize == 1); - assert(e[1].prevrawlensize == 5); - assert(e[2].prevrawlensize == 1); - - /* Deleting entry 1 will increase `prevrawlensize` for entry 2 */ - unsigned char *p = e[1].p; - zl = ziplistDelete(zl, &p); - - verify(zl, e); - - assert(e[0].prevrawlensize == 1); - assert(e[1].prevrawlensize == 5); - - printf("SUCCESS\n\n"); - zfree(zl); - } - - printf("Create long list and check indices:\n"); - { - unsigned long long start = usec(); - zl = ziplistNew(); - char buf[32]; - int i,len; - for (i = 0; i < 1000; i++) { - len = snprintf(buf,sizeof(buf),"%d",i); - zl = ziplistPush(zl,(unsigned char*)buf,len,ZIPLIST_TAIL); - } - for (i = 0; i < 1000; i++) { - p = ziplistIndex(zl,i); - assert(ziplistGet(p,NULL,NULL,&value)); - assert(i == value); - - p = ziplistIndex(zl,-i-1); - assert(ziplistGet(p,NULL,NULL,&value)); - assert(999-i == value); - } - printf("SUCCESS. usec=%lld\n\n", usec()-start); - zfree(zl); - } - - printf("Compare strings with ziplist entries:\n"); - { - zl = createList(); - p = ziplistIndex(zl,0); - if (!ziplistCompare(p,(unsigned char*)"hello",5)) { - printf("ERROR: not \"hello\"\n"); - return 1; - } - if (ziplistCompare(p,(unsigned char*)"hella",5)) { - printf("ERROR: \"hella\"\n"); - return 1; - } - - p = ziplistIndex(zl,3); - if (!ziplistCompare(p,(unsigned char*)"1024",4)) { - printf("ERROR: not \"1024\"\n"); - return 1; - } - if (ziplistCompare(p,(unsigned char*)"1025",4)) { - printf("ERROR: \"1025\"\n"); - return 1; - } - printf("SUCCESS\n\n"); - zfree(zl); - } - - printf("Merge test:\n"); - { - /* create list gives us: [hello, foo, quux, 1024] */ - zl = createList(); - unsigned char *zl2 = createList(); - - unsigned char *zl3 = ziplistNew(); - unsigned char *zl4 = ziplistNew(); - - if (ziplistMerge(&zl4, &zl4)) { - printf("ERROR: Allowed merging of one ziplist into itself.\n"); - return 1; - } - - /* Merge two empty ziplists, get empty result back. */ - zl4 = ziplistMerge(&zl3, &zl4); - ziplistRepr(zl4); - if (ziplistLen(zl4)) { - printf("ERROR: Merging two empty ziplists created entries.\n"); - return 1; - } - zfree(zl4); - - zl2 = ziplistMerge(&zl, &zl2); - /* merge gives us: [hello, foo, quux, 1024, hello, foo, quux, 1024] */ - ziplistRepr(zl2); - - if (ziplistLen(zl2) != 8) { - printf("ERROR: Merged length not 8, but: %u\n", ziplistLen(zl2)); - return 1; - } - - p = ziplistIndex(zl2,0); - if (!ziplistCompare(p,(unsigned char*)"hello",5)) { - printf("ERROR: not \"hello\"\n"); - return 1; - } - if (ziplistCompare(p,(unsigned char*)"hella",5)) { - printf("ERROR: \"hella\"\n"); - return 1; - } - - p = ziplistIndex(zl2,3); - if (!ziplistCompare(p,(unsigned char*)"1024",4)) { - printf("ERROR: not \"1024\"\n"); - return 1; - } - if (ziplistCompare(p,(unsigned char*)"1025",4)) { - printf("ERROR: \"1025\"\n"); - return 1; - } - - p = ziplistIndex(zl2,4); - if (!ziplistCompare(p,(unsigned char*)"hello",5)) { - printf("ERROR: not \"hello\"\n"); - return 1; - } - if (ziplistCompare(p,(unsigned char*)"hella",5)) { - printf("ERROR: \"hella\"\n"); - return 1; - } - - p = ziplistIndex(zl2,7); - if (!ziplistCompare(p,(unsigned char*)"1024",4)) { - printf("ERROR: not \"1024\"\n"); - return 1; - } - if (ziplistCompare(p,(unsigned char*)"1025",4)) { - printf("ERROR: \"1025\"\n"); - return 1; - } - printf("SUCCESS\n\n"); - zfree(zl); - } - - printf("Stress with random payloads of different encoding:\n"); - { - unsigned long long start = usec(); - int i,j,len,where; - unsigned char *p; - char buf[1024]; - int buflen; - list *ref; - listNode *refnode; - - /* Hold temp vars from ziplist */ - unsigned char *sstr; - unsigned int slen; - long long sval; - - iteration = accurate ? 20000 : 20; - for (i = 0; i < iteration; i++) { - zl = ziplistNew(); - ref = listCreate(); - listSetFreeMethod(ref, sdsfreegeneric); - len = rand() % 256; - - /* Create lists */ - for (j = 0; j < len; j++) { - where = (rand() & 1) ? ZIPLIST_HEAD : ZIPLIST_TAIL; - if (rand() % 2) { - buflen = randstring(buf,1,sizeof(buf)-1); - } else { - switch(rand() % 3) { - case 0: - buflen = snprintf(buf,sizeof(buf),"%lld",(0LL + rand()) >> 20); - break; - case 1: - buflen = snprintf(buf,sizeof(buf),"%lld",(0LL + rand())); - break; - case 2: - buflen = snprintf(buf,sizeof(buf),"%lld",(0LL + rand()) << 20); - break; - default: - assert(NULL); - } - } - - /* Add to ziplist */ - zl = ziplistPush(zl, (unsigned char*)buf, buflen, where); - - /* Add to reference list */ - if (where == ZIPLIST_HEAD) { - listAddNodeHead(ref,sdsnewlen(buf, buflen)); - } else if (where == ZIPLIST_TAIL) { - listAddNodeTail(ref,sdsnewlen(buf, buflen)); - } else { - assert(NULL); - } - } - - assert(listLength(ref) == ziplistLen(zl)); - for (j = 0; j < len; j++) { - /* Naive way to get elements, but similar to the stresser - * executed from the Tcl test suite. */ - p = ziplistIndex(zl,j); - refnode = listIndex(ref,j); - - assert(ziplistGet(p,&sstr,&slen,&sval)); - if (sstr == NULL) { - buflen = snprintf(buf,sizeof(buf),"%lld",sval); - } else { - buflen = slen; - memcpy(buf,sstr,buflen); - buf[buflen] = '\0'; - } - assert(memcmp(buf,listNodeValue(refnode),buflen) == 0); - } - zfree(zl); - listRelease(ref); - } - printf("Done. usec=%lld\n\n", usec()-start); - } - - printf("Stress with variable ziplist size:\n"); - { - unsigned long long start = usec(); - int maxsize = accurate ? 16384 : 16; - stress(ZIPLIST_HEAD,100000,maxsize,256); - stress(ZIPLIST_TAIL,100000,maxsize,256); - printf("Done. usec=%lld\n\n", usec()-start); - } - - /* Benchmarks */ - { - zl = ziplistNew(); - iteration = accurate ? 100000 : 100; - for (int i=0; i<iteration; i++) { - char buf[4096] = "asdf"; - zl = ziplistPush(zl, (unsigned char*)buf, 4, ZIPLIST_TAIL); - zl = ziplistPush(zl, (unsigned char*)buf, 40, ZIPLIST_TAIL); - zl = ziplistPush(zl, (unsigned char*)buf, 400, ZIPLIST_TAIL); - zl = ziplistPush(zl, (unsigned char*)buf, 4000, ZIPLIST_TAIL); - zl = ziplistPush(zl, (unsigned char*)"1", 1, ZIPLIST_TAIL); - zl = ziplistPush(zl, (unsigned char*)"10", 2, ZIPLIST_TAIL); - zl = ziplistPush(zl, (unsigned char*)"100", 3, ZIPLIST_TAIL); - zl = ziplistPush(zl, (unsigned char*)"1000", 4, ZIPLIST_TAIL); - zl = ziplistPush(zl, (unsigned char*)"10000", 5, ZIPLIST_TAIL); - zl = ziplistPush(zl, (unsigned char*)"100000", 6, ZIPLIST_TAIL); - } - - printf("Benchmark ziplistFind:\n"); - { - unsigned long long start = usec(); - for (int i = 0; i < 2000; i++) { - unsigned char *fptr = ziplistIndex(zl, ZIPLIST_HEAD); - fptr = ziplistFind(zl, fptr, (unsigned char*)"nothing", 7, 1); - } - printf("%lld\n", usec()-start); - } - - printf("Benchmark ziplistIndex:\n"); - { - unsigned long long start = usec(); - for (int i = 0; i < 2000; i++) { - ziplistIndex(zl, 99999); - } - printf("%lld\n", usec()-start); - } - - printf("Benchmark ziplistValidateIntegrity:\n"); - { - unsigned long long start = usec(); - for (int i = 0; i < 2000; i++) { - ziplistValidateIntegrity(zl, ziplistBlobLen(zl), 1, NULL, NULL); - } - printf("%lld\n", usec()-start); - } - - printf("Benchmark ziplistCompare with string\n"); - { - unsigned long long start = usec(); - for (int i = 0; i < 2000; i++) { - unsigned char *eptr = ziplistIndex(zl,0); - while (eptr != NULL) { - ziplistCompare(eptr,(unsigned char*)"nothing",7); - eptr = ziplistNext(zl,eptr); - } - } - printf("Done. usec=%lld\n", usec()-start); - } - - printf("Benchmark ziplistCompare with number\n"); - { - unsigned long long start = usec(); - for (int i = 0; i < 2000; i++) { - unsigned char *eptr = ziplistIndex(zl,0); - while (eptr != NULL) { - ziplistCompare(eptr,(unsigned char*)"99999",5); - eptr = ziplistNext(zl,eptr); - } - } - printf("Done. usec=%lld\n", usec()-start); - } - - zfree(zl); - } - - printf("Stress __ziplistCascadeUpdate:\n"); - { - char data[ZIP_BIG_PREVLEN]; - zl = ziplistNew(); - iteration = accurate ? 100000 : 100; - for (int i = 0; i < iteration; i++) { - zl = ziplistPush(zl, (unsigned char*)data, ZIP_BIG_PREVLEN-4, ZIPLIST_TAIL); - } - unsigned long long start = usec(); - zl = ziplistPush(zl, (unsigned char*)data, ZIP_BIG_PREVLEN-3, ZIPLIST_HEAD); - printf("Done. usec=%lld\n\n", usec()-start); - zfree(zl); - } - - printf("Edge cases of __ziplistCascadeUpdate:\n"); - { - /* Inserting a entry with data length greater than ZIP_BIG_PREVLEN-4 - * will leads to cascade update. */ - size_t s1 = ZIP_BIG_PREVLEN-4, s2 = ZIP_BIG_PREVLEN-3; - zl = ziplistNew(); - - zlentry e[4] = {{.prevrawlensize = 0, .prevrawlen = 0, .lensize = 0, - .len = 0, .headersize = 0, .encoding = 0, .p = NULL}}; - - zl = insertHelper(zl, 'a', s1, ZIPLIST_ENTRY_HEAD(zl)); - verify(zl, e); - - assert(e[0].prevrawlensize == 1 && e[0].prevrawlen == 0); - assert(compareHelper(zl, 'a', s1, 0)); - ziplistRepr(zl); - - /* No expand. */ - zl = insertHelper(zl, 'b', s1, ZIPLIST_ENTRY_HEAD(zl)); - verify(zl, e); - - assert(e[0].prevrawlensize == 1 && e[0].prevrawlen == 0); - assert(compareHelper(zl, 'b', s1, 0)); - - assert(e[1].prevrawlensize == 1 && e[1].prevrawlen == strEntryBytesSmall(s1)); - assert(compareHelper(zl, 'a', s1, 1)); - - ziplistRepr(zl); - - /* Expand(tail included). */ - zl = insertHelper(zl, 'c', s2, ZIPLIST_ENTRY_HEAD(zl)); - verify(zl, e); - - assert(e[0].prevrawlensize == 1 && e[0].prevrawlen == 0); - assert(compareHelper(zl, 'c', s2, 0)); - - assert(e[1].prevrawlensize == 5 && e[1].prevrawlen == strEntryBytesSmall(s2)); - assert(compareHelper(zl, 'b', s1, 1)); - - assert(e[2].prevrawlensize == 5 && e[2].prevrawlen == strEntryBytesLarge(s1)); - assert(compareHelper(zl, 'a', s1, 2)); - - ziplistRepr(zl); - - /* Expand(only previous head entry). */ - zl = insertHelper(zl, 'd', s2, ZIPLIST_ENTRY_HEAD(zl)); - verify(zl, e); - - assert(e[0].prevrawlensize == 1 && e[0].prevrawlen == 0); - assert(compareHelper(zl, 'd', s2, 0)); - - assert(e[1].prevrawlensize == 5 && e[1].prevrawlen == strEntryBytesSmall(s2)); - assert(compareHelper(zl, 'c', s2, 1)); - - assert(e[2].prevrawlensize == 5 && e[2].prevrawlen == strEntryBytesLarge(s2)); - assert(compareHelper(zl, 'b', s1, 2)); - - assert(e[3].prevrawlensize == 5 && e[3].prevrawlen == strEntryBytesLarge(s1)); - assert(compareHelper(zl, 'a', s1, 3)); - - ziplistRepr(zl); - - /* Delete from mid. */ - unsigned char *p = ziplistIndex(zl, 2); - zl = ziplistDelete(zl, &p); - verify(zl, e); - - assert(e[0].prevrawlensize == 1 && e[0].prevrawlen == 0); - assert(compareHelper(zl, 'd', s2, 0)); - - assert(e[1].prevrawlensize == 5 && e[1].prevrawlen == strEntryBytesSmall(s2)); - assert(compareHelper(zl, 'c', s2, 1)); - - assert(e[2].prevrawlensize == 5 && e[2].prevrawlen == strEntryBytesLarge(s2)); - assert(compareHelper(zl, 'a', s1, 2)); - - ziplistRepr(zl); - - zfree(zl); - } - - printf("__ziplistInsert nextdiff == -4 && reqlen < 4 (issue #7170):\n"); - { - zl = ziplistNew(); - - /* We set some values to almost reach the critical point - 254 */ - char A_252[253] = {0}, A_250[251] = {0}; - memset(A_252, 'A', 252); - memset(A_250, 'A', 250); - - /* After the rpush, the list look like: [one two A_252 A_250 three 10] */ - zl = ziplistPush(zl, (unsigned char*)"one", 3, ZIPLIST_TAIL); - zl = ziplistPush(zl, (unsigned char*)"two", 3, ZIPLIST_TAIL); - zl = ziplistPush(zl, (unsigned char*)A_252, strlen(A_252), ZIPLIST_TAIL); - zl = ziplistPush(zl, (unsigned char*)A_250, strlen(A_250), ZIPLIST_TAIL); - zl = ziplistPush(zl, (unsigned char*)"three", 5, ZIPLIST_TAIL); - zl = ziplistPush(zl, (unsigned char*)"10", 2, ZIPLIST_TAIL); - ziplistRepr(zl); - - p = ziplistIndex(zl, 2); - if (!ziplistCompare(p, (unsigned char*)A_252, strlen(A_252))) { - printf("ERROR: not \"A_252\"\n"); - return 1; - } - - /* When we remove A_252, the list became: [one two A_250 three 10] - * A_250's prev node became node two, because node two quite small - * So A_250's prevlenSize shrink to 1, A_250's total size became 253(1+2+250) - * The prev node of node three is still node A_250. - * We will not shrink the node three's prevlenSize, keep it at 5 bytes */ - zl = ziplistDelete(zl, &p); - ziplistRepr(zl); - - p = ziplistIndex(zl, 3); - if (!ziplistCompare(p, (unsigned char*)"three", 5)) { - printf("ERROR: not \"three\"\n"); - return 1; - } - - /* We want to insert a node after A_250, the list became: [one two A_250 10 three 10] - * Because the new node is quite small, node three prevlenSize will shrink to 1 */ - zl = ziplistInsert(zl, p, (unsigned char*)"10", 2); - ziplistRepr(zl); - - /* Last element should equal 10 */ - p = ziplistIndex(zl, -1); - if (!ziplistCompare(p, (unsigned char*)"10", 2)) { - printf("ERROR: not \"10\"\n"); - return 1; - } - - zfree(zl); - } - - printf("ALL TESTS PASSED!\n"); - return 0; -} -#endif |