Add Redis source code for testing

1 files changed, 157 insertions, 0 deletions

diff --git a/examples/redis-unstable/src/lolwut5.c b/examples/redis-unstable/src/lolwut5.c
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index 0000000..29f0a2f
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+++ b/examples/redis-unstable/src/lolwut5.c
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+/*
+ * Copyright (c) 2018-Present, Redis Ltd.
+ * 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).
+ *
+ * ----------------------------------------------------------------------------
+ *
+ * This file implements the LOLWUT command. The command should do something
+ * fun and interesting, and should be replaced by a new implementation at
+ * each new version of Redis.
+ */
+
+#include "server.h"
+#include "lolwut.h"
+#include <math.h>
+
+/* Translate a group of 8 pixels (2x4 vertical rectangle) to the corresponding
+ * braille character. The byte should correspond to the pixels arranged as
+ * follows, where 0 is the least significant bit, and 7 the most significant
+ * bit:
+ *
+ *   0 3
+ *   1 4
+ *   2 5
+ *   6 7
+ *
+ * The corresponding utf8 encoded character is set into the three bytes
+ * pointed by 'output'.
+ */
+#include <stdio.h>
+void lwTranslatePixelsGroup(int byte, char *output) {
+    int code = 0x2800 + byte;
+    /* Convert to unicode. This is in the U0800-UFFFF range, so we need to
+     * emit it like this in three bytes:
+     * 1110xxxx 10xxxxxx 10xxxxxx. */
+    output[0] = 0xE0 | (code >> 12);          /* 1110-xxxx */
+    output[1] = 0x80 | ((code >> 6) & 0x3F);  /* 10-xxxxxx */
+    output[2] = 0x80 | (code & 0x3F);         /* 10-xxxxxx */
+}
+
+/* Schotter, the output of LOLWUT of Redis 5, is a computer graphic art piece
+ * generated by Georg Nees in the 60s. It explores the relationship between
+ * caos and order.
+ *
+ * The function creates the canvas itself, depending on the columns available
+ * in the output display and the number of squares per row and per column
+ * requested by the caller. */
+lwCanvas *lwDrawSchotter(int console_cols, int squares_per_row, int squares_per_col) {
+    /* Calculate the canvas size. */
+    int canvas_width = console_cols*2;
+    int padding = canvas_width > 4 ? 2 : 0;
+    float square_side = (float)(canvas_width-padding*2) / squares_per_row;
+    int canvas_height = square_side * squares_per_col + padding*2;
+    lwCanvas *canvas = lwCreateCanvas(canvas_width, canvas_height, 0);
+
+    for (int y = 0; y < squares_per_col; y++) {
+        for (int x = 0; x < squares_per_row; x++) {
+            int sx = x * square_side + square_side/2 + padding;
+            int sy = y * square_side + square_side/2 + padding;
+            /* Rotate and translate randomly as we go down to lower
+             * rows. */
+            float angle = 0;
+            if (y > 1) {
+                float r1 = (float)rand() / (float) RAND_MAX / squares_per_col * y;
+                float r2 = (float)rand() / (float) RAND_MAX / squares_per_col * y;
+                float r3 = (float)rand() / (float) RAND_MAX / squares_per_col * y;
+                if (rand() % 2) r1 = -r1;
+                if (rand() % 2) r2 = -r2;
+                if (rand() % 2) r3 = -r3;
+                angle = r1;
+                sx += r2*square_side/3;
+                sy += r3*square_side/3;
+            }
+            lwDrawSquare(canvas,sx,sy,square_side,angle,1);
+        }
+    }
+
+    return canvas;
+}
+
+/* Converts the canvas to an SDS string representing the UTF8 characters to
+ * print to the terminal in order to obtain a graphical representation of the
+ * logical canvas. The actual returned string will require a terminal that is
+ * width/2 large and height/4 tall in order to hold the whole image without
+ * overflowing or scrolling, since each Barille character is 2x4. */
+static sds renderCanvas(lwCanvas *canvas) {
+    sds text = sdsempty();
+    for (int y = 0; y < canvas->height; y += 4) {
+        for (int x = 0; x < canvas->width; x += 2) {
+            /* We need to emit groups of 8 bits according to a specific
+             * arrangement. See lwTranslatePixelsGroup() for more info. */
+            int byte = 0;
+            if (lwGetPixel(canvas,x,y)) byte |= (1<<0);
+            if (lwGetPixel(canvas,x,y+1)) byte |= (1<<1);
+            if (lwGetPixel(canvas,x,y+2)) byte |= (1<<2);
+            if (lwGetPixel(canvas,x+1,y)) byte |= (1<<3);
+            if (lwGetPixel(canvas,x+1,y+1)) byte |= (1<<4);
+            if (lwGetPixel(canvas,x+1,y+2)) byte |= (1<<5);
+            if (lwGetPixel(canvas,x,y+3)) byte |= (1<<6);
+            if (lwGetPixel(canvas,x+1,y+3)) byte |= (1<<7);
+            char unicode[3];
+            lwTranslatePixelsGroup(byte,unicode);
+            text = sdscatlen(text,unicode,3);
+        }
+        if (y != canvas->height-1) text = sdscatlen(text,"\n",1);
+    }
+    return text;
+}
+
+/* The LOLWUT command:
+ *
+ * LOLWUT [terminal columns] [squares-per-row] [squares-per-col]
+ *
+ * By default the command uses 66 columns, 8 squares per row, 12 squares
+ * per column.
+ */
+void lolwut5Command(client *c) {
+    long cols = 66;
+    long squares_per_row = 8;
+    long squares_per_col = 12;
+
+    /* Parse the optional arguments if any. */
+    if (c->argc > 1 &&
+        getLongFromObjectOrReply(c,c->argv[1],&cols,NULL) != C_OK)
+        return;
+
+    if (c->argc > 2 &&
+        getLongFromObjectOrReply(c,c->argv[2],&squares_per_row,NULL) != C_OK)
+        return;
+
+    if (c->argc > 3 &&
+        getLongFromObjectOrReply(c,c->argv[3],&squares_per_col,NULL) != C_OK)
+        return;
+
+    /* Limits. We want LOLWUT to be always reasonably fast and cheap to execute
+     * so we have maximum number of columns, rows, and output resolution. */
+    if (cols < 1) cols = 1;
+    if (cols > 1000) cols = 1000;
+    if (squares_per_row < 1) squares_per_row = 1;
+    if (squares_per_row > 200) squares_per_row = 200;
+    if (squares_per_col < 1) squares_per_col = 1;
+    if (squares_per_col > 200) squares_per_col = 200;
+
+    /* Generate some computer art and reply. */
+    lwCanvas *canvas = lwDrawSchotter(cols,squares_per_row,squares_per_col);
+    sds rendered = renderCanvas(canvas);
+    rendered = sdscat(rendered,
+        "\nGeorg Nees - schotter, plotter on paper, 1968. Redis ver. ");
+    rendered = sdscat(rendered,REDIS_VERSION);
+    rendered = sdscatlen(rendered,"\n",1);
+    addReplyVerbatim(c,rendered,sdslen(rendered),"txt");
+    sdsfree(rendered);
+    lwFreeCanvas(canvas);
+}