ui-diff.c

   1 /* ui-diff.c: show diff between two blobs
   2  *
   3  * Copyright (C) 2006 Lars Hjemli
   4  *
   5  * Licensed under GNU General Public License v2
   6  *   (see COPYING for full license text)
   7  */
   8
   9 #include "cgit.h"
  10 #include "xdiff.h"
  11
  12 char *diff_buffer;
  13 int diff_buffer_size;
  14
  15
  16 /*
  17  * print a single line returned from xdiff
  18  */
  19 static void print_line(char *line, int len)
  20 {
  21         char *class = "ctx";
  22         char c = line[len-1];
  23
  24         if (line[0] == '+')
  25                 class = "add";
  26         else if (line[0] == '-')
  27                 class = "del";
  28         else if (line[0] == '@')
  29                 class = "hunk";
  30
  31         htmlf("<div class='%s'>", class);
  32         line[len-1] = '\0';
  33         html_txt(line);
  34         html("</div>");
  35         line[len-1] = c;
  36 }
  37
  38 /*
  39  * Receive diff-buffers from xdiff and concatenate them as
  40  * needed across multiple callbacks.
  41  *
  42  * This is basically a copy of xdiff-interface.c/xdiff_outf(),
  43  * ripped from git and modified to use globals instead of
  44  * a special callback-struct.
  45  */
  46 int diff_cb(void *priv_, mmbuffer_t *mb, int nbuf)
  47 {
  48         int i;
  49
  50         for (i = 0; i < nbuf; i++) {
  51                 if (mb[i].ptr[mb[i].size-1] != '\n') {
  52                         /* Incomplete line */
  53                         diff_buffer = xrealloc(diff_buffer,
  54                                                diff_buffer_size + mb[i].size);
  55                         memcpy(diff_buffer + diff_buffer_size,
  56                                mb[i].ptr, mb[i].size);
  57                         diff_buffer_size += mb[i].size;
  58                         continue;
  59                 }
  60
  61                 /* we have a complete line */
  62                 if (!diff_buffer) {
  63                         print_line(mb[i].ptr, mb[i].size);
  64                         continue;
  65                 }
  66                 diff_buffer = xrealloc(diff_buffer,
  67                                        diff_buffer_size + mb[i].size);
  68                 memcpy(diff_buffer + diff_buffer_size, mb[i].ptr, mb[i].size);
  69                 print_line(diff_buffer, diff_buffer_size + mb[i].size);
  70                 free(diff_buffer);
  71                 diff_buffer = NULL;
  72                 diff_buffer_size = 0;
  73         }
  74         if (diff_buffer) {
  75                 print_line(diff_buffer, diff_buffer_size);
  76                 free(diff_buffer);
  77                 diff_buffer = NULL;
  78                 diff_buffer_size = 0;
  79         }
  80         return 0;
  81 }
  82
  83 static int load_mmfile(mmfile_t *file, const unsigned char *sha1)
  84 {
  85         char type[20];
  86
  87         if (is_null_sha1(sha1)) {
  88                 file->ptr = (char *)"";
  89                 file->size = 0;
  90         } else {
  91                 file->ptr = read_sha1_file(sha1, type, &file->size);
  92         }
  93         return 1;
  94 }
  95
  96 static void run_diff(const unsigned char *sha1, const unsigned char *sha2)
  97 {
  98         mmfile_t file1, file2;
  99         xpparam_t diff_params;
 100         xdemitconf_t emit_params;
 101         xdemitcb_t emit_cb;
 102
 103         if (!load_mmfile(&file1, sha1) || !load_mmfile(&file2, sha2)) {
 104                 cgit_print_error("Unable to load files for diff");
 105                 return;
 106         }
 107
 108         diff_params.flags = XDF_NEED_MINIMAL;
 109
 110         emit_params.ctxlen = 3;
 111         emit_params.flags = XDL_EMIT_FUNCNAMES;
 112
 113         emit_cb.outf = diff_cb;
 114
 115         xdl_diff(&file1, &file2, &diff_params, &emit_params, &emit_cb);
 116 }
 117
 118
 119
 120 void cgit_print_diff(const char *old_hex, const char *new_hex)
 121 {
 122         unsigned char sha1[20], sha2[20];
 123
 124         get_sha1(old_hex, sha1);
 125         get_sha1(new_hex, sha2);
 126
 127         html("<h2>diff</h2>\n");
 128         html("<table class='diff'><tr><td>");
 129         run_diff(sha1, sha2);
 130         html("</td></tr></table>");
 131 }