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