include/got_diff.h

   1 /*
   2  * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 /*
  18  * Compute the differences between two blobs and write unified diff text
  19  * to the provided output FILE. Two const char * diff header labels may
  20  * be provided which will be used to identify each blob in the diff output.
  21  * If a label is NULL, use the blob's SHA1 checksum instead.
  22  * The number of context lines to show in the diff must be specified as well.
  23  * Whitespace differences may optionally be ignored.
  24  * If not NULL, the two initial output arguments will be populated with an
  25  * array of line offsets for, and the number of lines in, the unidiff text.
  26  */
  27 const struct got_error *got_diff_blob(off_t **, size_t *,
  28     struct got_blob_object *, struct got_blob_object *,
  29     const char *, const char *, int, int, int, FILE *);
  30
  31 /*
  32  * Compute the differences between a blob and a file and write unified diff
  33  * text to the provided output file. The file's size must be provided, as
  34  * well as a const char * diff header label which identifies the file.
  35  * An optional const char * diff header label for the blob may be provided, too.
  36  * The number of context lines to show in the diff must be specified as well.
  37  * Whitespace differences may optionally be ignored.
  38  */
  39 const struct got_error *got_diff_blob_file(struct got_blob_object *,
  40     const char *, FILE *, size_t, const char *, int, int, int, FILE *);
  41
  42 /*
  43  * A callback function invoked to handle the differences between two blobs
  44  * when diffing trees with got_diff_tree(). This callback receives two blobs,
  45  * their respective IDs, and two corresponding paths within the diffed trees.
  46  * The first blob contains content from the old side of the diff, and
  47  * the second blob contains content on the new side of the diff.
  48  * The set of arguments relating to either blob may be NULL to indicate
  49  * that no content is present on its respective side of the diff.
  50  * File modes from relevant tree objects which contain the blobs may
  51  * also be passed. These will be zero if not available.
  52  */
  53 typedef const struct got_error *(*got_diff_blob_cb)(void *,
  54     struct got_blob_object *, struct got_blob_object *,
  55     struct got_object_id *, struct got_object_id *,
  56     const char *, const char *, mode_t, mode_t, struct got_repository *);
  57
  58 /*
  59  * A pre-defined implementation of got_diff_blob_cb() which appends unidiff
  60  * output to a file. The caller must allocate and fill in the argument
  61  * structure.
  62  */
  63 struct got_diff_blob_output_unidiff_arg {
  64         FILE *outfile;          /* Unidiff text will be written here. */
  65         int diff_context;       /* Sets the number of context lines. */
  66         int ignore_whitespace;  /* Ignore whitespace differences. */
  67         int force_text_diff;    /* Assume text even if binary data detected. */
  68
  69         /*
  70          * The number of lines contained in produced unidiff text output,
  71          * and an array of byte offsets to each line. May be initialized to
  72          * zero and NULL to ignore line offsets. If not NULL, then the line
  73          * offsets array will be populated. Optionally, the array can be
  74          * pre-populated with line offsets, with nlines > 0 indicating
  75          * the length of the pre-populated array. This is useful if the
  76          * output file already contains some lines of text.
  77          * The array will be grown as needed to accomodate additional line
  78          * offsets, and the last offset found in a pre-populated array will
  79          * be added to all subsequent offsets.
  80          */
  81         size_t nlines;
  82         off_t *line_offsets;    /* Dispose of with free(3) when done. */
  83 };
  84 const struct got_error *got_diff_blob_output_unidiff(void *,
  85     struct got_blob_object *, struct got_blob_object *,
  86     struct got_object_id *, struct got_object_id *,
  87     const char *, const char *, mode_t, mode_t, struct got_repository *);
  88
  89 /*
  90  * Compute the differences between two trees and invoke the provided
  91  * got_diff_blob_cb() callback when content differs.
  92  * Diffing of blob content can be suppressed by passing zero for the
  93  * 'diff_content' parameter. The callback will then only receive blob
  94  * object IDs and diff labels, but NULL pointers instead of blob objects.
  95  */
  96 const struct got_error *got_diff_tree(struct got_tree_object *,
  97     struct got_tree_object *, const char *, const char *,
  98     struct got_repository *, got_diff_blob_cb cb, void *cb_arg, int);
  99
 100 /*
 101  * A pre-defined implementation of got_diff_blob_cb() which collects a list
 102  * of file paths that differ between two trees.
 103  * The caller must allocate and initialize a got_pathlist_head * argument.
 104  * Data pointers of entries added to the path list will point to a struct
 105  * got_diff_changed_path object.
 106  * The caller is expected to free both the path and data pointers of all
 107  * entries on the path list.
 108  */
 109 struct got_diff_changed_path {
 110         /*
 111          * The modification status of this path. It can be GOT_STATUS_ADD,
 112          * GOT_STATUS_DELETE, GOT_STATUS_MODIFY, or GOT_STATUS_MODE_CHANGE.
 113          */
 114         int status;
 115 };
 116 const struct got_error *got_diff_tree_collect_changed_paths(void *,
 117     struct got_blob_object *, struct got_blob_object *,
 118     struct got_object_id *, struct got_object_id *,
 119     const char *, const char *, mode_t, mode_t, struct got_repository *);
 120
 121 /*
 122  * Diff two objects, assuming both objects are blobs. Two const char * diff
 123  * header labels may be provided which will be used to identify each blob in
 124  * the diff output. If a label is NULL, use the blob's SHA1 checksum instead.
 125  * The number of context lines to show in the diff must be specified as well.
 126  * Write unified diff text to the provided output FILE.
 127  * If not NULL, the two initial output arguments will be populated with an
 128  * array of line offsets for, and the number of lines in, the unidiff text.
 129  */
 130 const struct got_error *got_diff_objects_as_blobs(off_t **, size_t *,
 131     struct got_object_id *, struct got_object_id *,
 132     const char *, const char *, int, int, int,
 133     struct got_repository *, FILE *);
 134
 135 /*
 136  * Diff two objects, assuming both objects are trees. Two const char * diff
 137  * header labels may be provided which will be used to identify each blob in
 138  * the trees. If a label is NULL, use the blob's SHA1 checksum instead.
 139  * The number of context lines to show in diffs must be specified.
 140  * Write unified diff text to the provided output FILE.
 141  * If not NULL, the two initial output arguments will be populated with an
 142  * array of line offsets for, and the number of lines in, the unidiff text.
 143  */
 144 const struct got_error *got_diff_objects_as_trees(off_t **, size_t *,
 145     struct got_object_id *, struct got_object_id *, char *, char *,
 146     int, int, int, struct got_repository *, FILE *);
 147
 148 /*
 149  * Diff two objects, assuming both objects are commits.
 150  * The number of context lines to show in diffs must be specified.
 151  * Write unified diff text to the provided output FILE.
 152  * If not NULL, the two initial output arguments will be populated with an
 153  * array of line offsets for, and the number of lines in, the unidiff text.
 154  */
 155 const struct got_error *got_diff_objects_as_commits(off_t **, size_t *,
 156     struct got_object_id *, struct got_object_id *, int, int, int,
 157     struct got_repository *, FILE *);
 158
 159 #define GOT_DIFF_MAX_CONTEXT    64