lib/diff_output.h

   1 /* Diff output generators and invocation shims. */
   2 /*
   3  * Copyright (c) 2020 Neels Hofmeyr <neels@hofmeyr.de>
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 struct diff_input_info {
  19         const char *left_path;
  20         const char *right_path;
  21
  22         /* Set by caller of diff_output_* functions. */
  23         int flags;
  24 #define DIFF_INPUT_LEFT_NONEXISTENT     0x00000001
  25 #define DIFF_INPUT_RIGHT_NONEXISTENT    0x00000002
  26 };
  27
  28 struct diff_output_info {
  29         /*
  30          * Byte offset to each line in the generated output file.
  31          * The total number of lines in the file is line_offsets.len - 1.
  32          * The last offset in this array corresponds to end-of-file.
  33          */
  34         ARRAYLIST(off_t) line_offsets;
  35         /*
  36          * Type (i.e., context, minus, plus) of each line generated by the diff.
  37          * nb. 0x00 to 0x3b reserved for client-defined line types.
  38          */
  39         ARRAYLIST(uint8_t) line_types;
  40 #define DIFF_LINE_HUNK          0x3c
  41 #define DIFF_LINE_MINUS         0x3d
  42 #define DIFF_LINE_PLUS          0x3e
  43 #define DIFF_LINE_CONTEXT       0x3f
  44 #define DIFF_LINE_NONE          0x40  /* binary or no EOF newline msg, etc. */
  45 };
  46
  47 void diff_output_info_free(struct diff_output_info *output_info);
  48
  49 struct diff_chunk_context {
  50         struct diff_range chunk;
  51         struct diff_range left, right;
  52 };
  53
  54 int diff_output_plain(struct diff_output_info **output_info, FILE *dest,
  55                         const struct diff_input_info *info,
  56                         const struct diff_result *result,
  57                         int hunk_headers_only);
  58 int diff_output_unidiff(struct diff_output_info **output_info,
  59                         FILE *dest, const struct diff_input_info *info,
  60                         const struct diff_result *result,
  61                         unsigned int context_lines);
  62 int diff_output_edscript(struct diff_output_info **output_info,
  63                          FILE *dest, const struct diff_input_info *info,
  64                          const struct diff_result *result);
  65 int diff_chunk_get_left_start(const struct diff_chunk *c,
  66                               const struct diff_result *r,
  67                               int context_lines);
  68 int diff_chunk_get_left_end(const struct diff_chunk *c,
  69                             const struct diff_result *r,
  70                             int context_lines);
  71 int diff_chunk_get_right_start(const struct diff_chunk *c,
  72                                const struct diff_result *r,
  73                                int context_lines);
  74 int diff_chunk_get_right_end(const struct diff_chunk *c,
  75                              const struct diff_result *r,
  76                              int context_lines);
  77 off_t diff_chunk_get_left_start_pos(const struct diff_chunk *c);
  78 off_t diff_chunk_get_right_start_pos(const struct diff_chunk *c);
  79 struct diff_chunk *diff_chunk_get(const struct diff_result *r, int chunk_idx);
  80 int diff_chunk_get_left_count(struct diff_chunk *c);
  81 int diff_chunk_get_right_count(struct diff_chunk *c);
  82 void diff_chunk_context_get(struct diff_chunk_context *cc,
  83                                  const struct diff_result *r,
  84                                  int chunk_idx, int context_lines);
  85 void diff_chunk_context_load_change(struct diff_chunk_context *cc,
  86                                     int *nchunks_used,
  87                                     struct diff_result *result,
  88                                     int start_chunk_idx,
  89                                     int context_lines);
  90
  91 struct diff_output_unidiff_state;
  92 struct diff_output_unidiff_state *diff_output_unidiff_state_alloc(void);
  93 void diff_output_unidiff_state_reset(struct diff_output_unidiff_state *state);
  94 void diff_output_unidiff_state_free(struct diff_output_unidiff_state *state);
  95 int diff_output_unidiff_chunk(struct diff_output_info **output_info, FILE *dest,
  96                           struct diff_output_unidiff_state *state,
  97                           const struct diff_input_info *info,
  98                           const struct diff_result *result,
  99                           const struct diff_chunk_context *cc);
 100 int diff_output_chunk_left_version(struct diff_output_info **output_info,
 101                                FILE *dest,
 102                                const struct diff_input_info *info,
 103                                const struct diff_result *result,
 104                                const struct diff_chunk_context *cc);
 105 int diff_output_chunk_right_version(struct diff_output_info **output_info,
 106                                 FILE *dest,
 107                                 const struct diff_input_info *info,
 108                                 const struct diff_result *result,
 109                                 const struct diff_chunk_context *cc);
 110
 111 const char *diff_output_get_label_left(const struct diff_input_info *info);
 112 const char *diff_output_get_label_right(const struct diff_input_info *info);