1 files changed, 188 insertions, 0 deletions

diff --git a/examples/redis-unstable/src/rio.h b/examples/redis-unstable/src/rio.h
new file mode 100644
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+++ b/examples/redis-unstable/src/rio.h
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+/*
+ * Copyright (c) 2009-Present, Redis Ltd.
+ * All rights reserved.
+ *
+ * Copyright (c) 2024-present, Valkey contributors.
+ * All rights reserved.
+ *
+ * Licensed under your choice of (a) the Redis Source Available License 2.0
+ * (RSALv2); or (b) the Server Side Public License v1 (SSPLv1); or (c) the
+ * GNU Affero General Public License v3 (AGPLv3).
+ *
+ * Portions of this file are available under BSD3 terms; see REDISCONTRIBUTIONS for more information.
+ */
+
+
+#ifndef __REDIS_RIO_H
+#define __REDIS_RIO_H
+
+#include <stdio.h>
+#include <stdint.h>
+#include "sds.h"
+#include "connection.h"
+
+#define RIO_FLAG_READ_ERROR (1<<0)
+#define RIO_FLAG_WRITE_ERROR (1<<1)
+
+#define RIO_TYPE_FILE (1<<0)
+#define RIO_TYPE_BUFFER (1<<1)
+#define RIO_TYPE_CONN (1<<2)
+#define RIO_TYPE_FD (1<<3)
+
+struct _rio {
+    /* Backend functions.
+     * Since this functions do not tolerate short writes or reads the return
+     * value is simplified to: zero on error, non zero on complete success. */
+    size_t (*read)(struct _rio *, void *buf, size_t len);
+    size_t (*write)(struct _rio *, const void *buf, size_t len);
+    off_t (*tell)(struct _rio *);
+    int (*flush)(struct _rio *);
+    /* The update_cksum method if not NULL is used to compute the checksum of
+     * all the data that was read or written so far. The method should be
+     * designed so that can be called with the current checksum, and the buf
+     * and len fields pointing to the new block of data to add to the checksum
+     * computation. */
+    void (*update_cksum)(struct _rio *, const void *buf, size_t len);
+
+    /* The current checksum and flags (see RIO_FLAG_*) */
+    uint64_t cksum, flags;
+
+    /* number of bytes read or written */
+    size_t processed_bytes;
+
+    /* maximum single read or write chunk size */
+    size_t max_processing_chunk;
+
+    /* Backend-specific vars. */
+    union {
+        /* In-memory buffer target. */
+        struct {
+            sds ptr;
+            off_t pos;
+        } buffer;
+        /* Stdio file pointer target. */
+        struct {
+            FILE *fp;
+            off_t buffered; /* Bytes written since last fsync. */
+            off_t autosync; /* fsync after 'autosync' bytes written. */
+            unsigned reclaim_cache:1; /* A flag to indicate reclaim cache after fsync */
+        } file;
+        /* Connection object (used to read from socket) */
+        struct {
+            connection *conn;   /* Connection */
+            off_t pos;    /* pos in buf that was returned */
+            sds buf;      /* buffered data */
+            size_t read_limit;  /* don't allow to buffer/read more than that */
+            size_t read_so_far; /* amount of data read from the rio (not buffered) */
+        } conn;
+        /* FD target (used to write to pipe). */
+        struct {
+            int fd;       /* File descriptor. */
+            off_t pos;
+            sds buf;
+        } fd;
+        /* Multiple connections target (used to write to N sockets). */
+        struct {
+            struct {
+                connection *conn; /* Connection */
+                int failed;       /* If write failed on this connection. */
+            } *dst;
+
+            size_t n_dst;        /* Number of connections */
+            off_t pos;           /* Number of sent bytes */
+            sds buf;
+        } connset;
+    } io;
+};
+
+typedef struct _rio rio;
+
+/* The following functions are our interface with the stream. They'll call the
+ * actual implementation of read / write / tell, and will update the checksum
+ * if needed. */
+
+static inline size_t rioWrite(rio *r, const void *buf, size_t len) {
+    if (r->flags & (RIO_FLAG_WRITE_ERROR)) return 0;
+    while (len) {
+        size_t bytes_to_write = (r->max_processing_chunk && r->max_processing_chunk < len) ? r->max_processing_chunk : len;
+        if (r->update_cksum) r->update_cksum(r,buf,bytes_to_write);
+        if (r->write(r,buf,bytes_to_write) == 0) {
+            r->flags |= RIO_FLAG_WRITE_ERROR;
+            return 0;
+        }
+        buf = (char*)buf + bytes_to_write;
+        len -= bytes_to_write;
+        r->processed_bytes += bytes_to_write;
+    }
+    return 1;
+}
+
+static inline size_t rioRead(rio *r, void *buf, size_t len) {
+    if (r->flags & (RIO_FLAG_READ_ERROR)) return 0;
+    while (len) {
+        size_t bytes_to_read = (r->max_processing_chunk && r->max_processing_chunk < len) ? r->max_processing_chunk : len;
+        if (r->read(r,buf,bytes_to_read) == 0) {
+            r->flags |= RIO_FLAG_READ_ERROR;
+            return 0;
+        }
+        if (r->update_cksum) r->update_cksum(r,buf,bytes_to_read);
+        buf = (char*)buf + bytes_to_read;
+        len -= bytes_to_read;
+        r->processed_bytes += bytes_to_read;
+    }
+    return 1;
+}
+
+static inline off_t rioTell(rio *r) {
+    return r->tell(r);
+}
+
+static inline int rioFlush(rio *r) {
+    return r->flush(r);
+}
+
+/* Abort RIO asynchronously by setting read and write error flags. Subsequent
+ * rioRead()/rioWrite() calls will fail, letting the caller terminate safely. */
+static inline void rioAbort(rio *r) {
+    r->flags |= (RIO_FLAG_READ_ERROR | RIO_FLAG_WRITE_ERROR);
+}
+
+/* This function allows to know if there was a read error in any past
+ * operation, since the rio stream was created or since the last call
+ * to rioClearError(). */
+static inline int rioGetReadError(rio *r) {
+    return (r->flags & RIO_FLAG_READ_ERROR) != 0;
+}
+
+/* Like rioGetReadError() but for write errors. */
+static inline int rioGetWriteError(rio *r) {
+    return (r->flags & RIO_FLAG_WRITE_ERROR) != 0;
+}
+
+static inline void rioClearErrors(rio *r) {
+    r->flags &= ~(RIO_FLAG_READ_ERROR|RIO_FLAG_WRITE_ERROR);
+}
+
+void rioInitWithFile(rio *r, FILE *fp);
+void rioInitWithBuffer(rio *r, sds s);
+void rioInitWithConn(rio *r, connection *conn, size_t read_limit);
+void rioInitWithFd(rio *r, int fd);
+void rioInitWithConnset(rio *r, connection **conns, size_t n_conns);
+
+void rioFreeFd(rio *r);
+void rioFreeConn(rio *r, sds* out_remainingBufferedData);
+void rioFreeConnset(rio *r);
+
+size_t rioWriteBulkCount(rio *r, char prefix, long count);
+size_t rioWriteBulkString(rio *r, const char *buf, size_t len);
+size_t rioWriteBulkLongLong(rio *r, long long l);
+size_t rioWriteBulkDouble(rio *r, double d);
+
+struct redisObject;
+int rioWriteBulkObject(rio *r, struct redisObject *obj);
+
+void rioGenericUpdateChecksum(rio *r, const void *buf, size_t len);
+void rioSetAutoSync(rio *r, off_t bytes);
+void rioSetReclaimCache(rio *r, int enabled); 
+uint8_t rioCheckType(rio *r);
+#endif