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Diffstat (limited to 'src/sparkline.c')
| -rw-r--r-- | src/sparkline.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/src/sparkline.c b/src/sparkline.c new file mode 100644 index 0000000..67482c7 --- /dev/null +++ b/src/sparkline.c @@ -0,0 +1,176 @@ +/* sparkline.c -- ASCII Sparklines + * This code is modified from http://github.com/antirez/aspark and adapted + * in order to return SDS strings instead of outputting directly to + * the terminal. + * + * --------------------------------------------------------------------------- + * + * Copyright(C) 2011-2014 Salvatore Sanfilippo <antirez@gmail.com> + * 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. + * + * 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 "server.h" + +#include <math.h> + +/* This is the charset used to display the graphs, but multiple rows are used + * to increase the resolution. */ +static char charset[] = "_-`"; +static char charset_fill[] = "_o#"; +static int charset_len = sizeof(charset)-1; +static int label_margin_top = 1; + +/* ---------------------------------------------------------------------------- + * Sequences are arrays of samples we use to represent data to turn + * into sparklines. This is the API in order to generate a sparkline: + * + * struct sequence *seq = createSparklineSequence(); + * sparklineSequenceAddSample(seq, 10, NULL); + * sparklineSequenceAddSample(seq, 20, NULL); + * sparklineSequenceAddSample(seq, 30, "last sample label"); + * sds output = sparklineRender(sdsempty(), seq, 80, 4, SPARKLINE_FILL); + * freeSparklineSequence(seq); + * ------------------------------------------------------------------------- */ + +/* Create a new sequence. */ +struct sequence *createSparklineSequence(void) { + struct sequence *seq = zmalloc(sizeof(*seq)); + seq->length = 0; + seq->samples = NULL; + return seq; +} + +/* Add a new sample into a sequence. */ +void sparklineSequenceAddSample(struct sequence *seq, double value, char *label) { + label = (label == NULL || label[0] == '\0') ? NULL : zstrdup(label); + if (seq->length == 0) { + seq->min = seq->max = value; + } else { + if (value < seq->min) seq->min = value; + else if (value > seq->max) seq->max = value; + } + seq->samples = zrealloc(seq->samples,sizeof(struct sample)*(seq->length+1)); + seq->samples[seq->length].value = value; + seq->samples[seq->length].label = label; + seq->length++; + if (label) seq->labels++; +} + +/* Free a sequence. */ +void freeSparklineSequence(struct sequence *seq) { + int j; + + for (j = 0; j < seq->length; j++) + zfree(seq->samples[j].label); + zfree(seq->samples); + zfree(seq); +} + +/* ---------------------------------------------------------------------------- + * ASCII rendering of sequence + * ------------------------------------------------------------------------- */ + +/* Render part of a sequence, so that render_sequence() call call this function + * with different parts in order to create the full output without overflowing + * the current terminal columns. */ +sds sparklineRenderRange(sds output, struct sequence *seq, int rows, int offset, int len, int flags) { + int j; + double relmax = seq->max - seq->min; + int steps = charset_len*rows; + int row = 0; + char *chars = zmalloc(len); + int loop = 1; + int opt_fill = flags & SPARKLINE_FILL; + int opt_log = flags & SPARKLINE_LOG_SCALE; + + if (opt_log) { + relmax = log(relmax+1); + } else if (relmax == 0) { + relmax = 1; + } + + while(loop) { + loop = 0; + memset(chars,' ',len); + for (j = 0; j < len; j++) { + struct sample *s = &seq->samples[j+offset]; + double relval = s->value - seq->min; + int step; + + if (opt_log) relval = log(relval+1); + step = (int) (relval*steps)/relmax; + if (step < 0) step = 0; + if (step >= steps) step = steps-1; + + if (row < rows) { + /* Print the character needed to create the sparkline */ + int charidx = step-((rows-row-1)*charset_len); + loop = 1; + if (charidx >= 0 && charidx < charset_len) { + chars[j] = opt_fill ? charset_fill[charidx] : + charset[charidx]; + } else if(opt_fill && charidx >= charset_len) { + chars[j] = '|'; + } + } else { + /* Labels spacing */ + if (seq->labels && row-rows < label_margin_top) { + loop = 1; + break; + } + /* Print the label if needed. */ + if (s->label) { + int label_len = strlen(s->label); + int label_char = row - rows - label_margin_top; + + if (label_len > label_char) { + loop = 1; + chars[j] = s->label[label_char]; + } + } + } + } + if (loop) { + row++; + output = sdscatlen(output,chars,len); + output = sdscatlen(output,"\n",1); + } + } + zfree(chars); + return output; +} + +/* Turn a sequence into its ASCII representation */ +sds sparklineRender(sds output, struct sequence *seq, int columns, int rows, int flags) { + int j; + + for (j = 0; j < seq->length; j += columns) { + int sublen = (seq->length-j) < columns ? (seq->length-j) : columns; + + if (j != 0) output = sdscatlen(output,"\n",1); + output = sparklineRenderRange(output, seq, rows, j, sublen, flags); + } + return output; +} + |