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 enum got_diff_algorithm {
  18         GOT_DIFF_ALGORITHM_MYERS,
  19         GOT_DIFF_ALGORITHM_PATIENCE,
  20 };
  21
  22 /*
  23  * List of all line types in a diff (including '{got,tog} log' lines).
  24  * XXX GOT_DIFF_LINE_HUNK to GOT_DIFF_LINE_NONE inclusive must map to the
  25  * DIFF_LINE_* macro counterparts defined in lib/diff_output.h (i.e., 60-64).
  26  */
  27 enum got_diff_line_type {
  28         GOT_DIFF_LINE_LOGMSG,
  29         GOT_DIFF_LINE_AUTHOR,
  30         GOT_DIFF_LINE_DATE,
  31         GOT_DIFF_LINE_CHANGES,
  32         GOT_DIFF_LINE_META,
  33         GOT_DIFF_LINE_BLOB_MIN,
  34         GOT_DIFF_LINE_BLOB_PLUS,
  35         GOT_DIFF_LINE_HUNK = 60,
  36         GOT_DIFF_LINE_MINUS,
  37         GOT_DIFF_LINE_PLUS,
  38         GOT_DIFF_LINE_CONTEXT,
  39         GOT_DIFF_LINE_NONE
  40 };
  41
  42 struct got_diff_line {
  43         off_t   offset;
  44         uint8_t type;
  45 };
  46
  47 struct got_diffstat_cb_arg;
  48
  49 /*
  50  * Compute the differences between two blobs and write unified diff text
  51  * to the provided output file. Two open temporary files must be provided
  52  * for internal use; these files can be obtained from got_opentemp() and
  53  * must be closed by the caller.
  54  * If one of the blobs being diffed does not exist, all corresponding
  55  * blob object arguments should be set to NULL.
  56  * Two const char * diff header labels may be provided which will be used
  57  * to identify each blob in the diff output.
  58  * If a label is NULL, use the blob's hash instead.
  59  * The number of context lines to show in the diff must be specified as well.
  60  * Whitespace differences may optionally be ignored.
  61  * If not NULL, the two initial output arguments will be populated with an
  62  * array of line offsets for, and the number of lines in, the unidiff text.
  63  */
  64 const struct got_error *got_diff_blob(struct got_diff_line **, size_t *,
  65     struct got_blob_object *, struct got_blob_object *, FILE *, FILE *,
  66     const char *, const char *, enum got_diff_algorithm, int, int, int,
  67     struct got_diffstat_cb_arg *, FILE *);
  68
  69 /*
  70  * Compute the differences between a blob and a file and write unified diff
  71  * text to the provided output file. The blob object, its content, and its
  72  * size must be provided. The file's size must be provided, as well as a
  73  * const char * diff header label which identifies the file.
  74  * An optional const char * diff header label for the blob may be provided, too.
  75  * The number of context lines to show in the diff must be specified as well.
  76  * Whitespace differences may optionally be ignored.
  77  */
  78 const struct got_error *got_diff_blob_file(struct got_blob_object *, FILE *,
  79     off_t, const char *, FILE *, int, struct stat *, const char *,
  80     enum got_diff_algorithm, int, int, int, struct got_diffstat_cb_arg *,
  81     FILE *);
  82
  83 /*
  84  * A callback function invoked to handle the differences between two blobs
  85  * when diffing trees with got_diff_tree(). This callback receives two blobs,
  86  * their respective IDs, and two corresponding paths within the diffed trees.
  87  * The first blob contains content from the old side of the diff, and
  88  * the second blob contains content on the new side of the diff.
  89  * Two open temporary files must be provided for internal use; these files
  90  * can be obtained from got_opentemp() and must be closed by the caller.
  91  * The blob object argument for either blob may be NULL to indicate
  92  * that no content is present on its respective side of the diff.
  93  * File modes from relevant tree objects which contain the blobs may
  94  * also be passed. These will be zero if not available.
  95  */
  96 typedef const struct got_error *(*got_diff_blob_cb)(void *,
  97     struct got_blob_object *, struct got_blob_object *, FILE *, FILE *,
  98     struct got_object_id *, struct got_object_id *,
  99     const char *, const char *, mode_t, mode_t, struct got_repository *);
 100
 101 /*
 102  * A pre-defined implementation of got_diff_blob_cb() which appends unidiff
 103  * output to a file. The caller must allocate and fill in the argument
 104  * structure.
 105  */
 106 struct got_diff_blob_output_unidiff_arg {
 107         FILE *outfile;          /* Unidiff text will be written here. */
 108         int diff_context;       /* Sets the number of context lines. */
 109         int ignore_whitespace;  /* Ignore whitespace differences. */
 110         int force_text_diff;    /* Assume text even if binary data detected. */
 111         struct got_diffstat_cb_arg *diffstat; /* Compute diffstat of changes */
 112         enum got_diff_algorithm diff_algo; /* Diffing algorithm to use. */
 113
 114         /*
 115          * The number of lines contained in produced unidiff text output,
 116          * and an array of got_diff_lines with byte offset and line type to
 117          * each line. May be initialized to zero and NULL to ignore line
 118          * metadata. If not NULL, then the array of line offsets and types will
 119          * be populated. Optionally, the array can be pre-populated with line
 120          * offsets and types, with nlines > 0 indicating the length of the
 121          * pre-populated array.  This is useful if the output file already
 122          * contains some lines of text.  The array will be grown as needed to
 123          * accommodate additional offsets and types, and the last offset found
 124          * in a pre-populated array will be added to all subsequent offsets.
 125          */
 126         size_t nlines;
 127         struct got_diff_line *lines; /* Dispose of with free(3) when done. */
 128 };
 129 const struct got_error *got_diff_blob_output_unidiff(void *,
 130     struct got_blob_object *, struct got_blob_object *, FILE *, FILE *,
 131     struct got_object_id *, struct got_object_id *,
 132     const char *, const char *, mode_t, mode_t, struct got_repository *);
 133
 134 /*
 135  * Compute the differences between two trees and invoke the provided
 136  * got_diff_blob_cb() callback when content differs.
 137  * Diffing of blob content can be suppressed by passing zero for the
 138  * 'diff_content' parameter. The callback will then only receive blob
 139  * object IDs and diff labels, but NULL pointers instead of blob objects.
 140  * If 'diff_content' is set, two open temporary FILEs and two open
 141  * temporary file descriptors must be provided for internal use; these
 142  * files can be obtained from got_opentemp() and got_opentempfd(),
 143  * and must be closed by the caller. Otherwise the files can be NULL.
 144  * The set of arguments relating to either tree may be NULL to indicate
 145  * that no content is present on its respective side of the diff.
 146  */
 147 const struct got_error *got_diff_tree(struct got_tree_object *,
 148     struct got_tree_object *, FILE *, FILE *, int, int,
 149     const char *, const char *,
 150     struct got_repository *, got_diff_blob_cb cb, void *cb_arg, int);
 151
 152 /*
 153  * Pre-defined implementations of got_diff_blob_cb(): the first of which
 154  * collects a list of file paths that differ between two trees; the second
 155  * also computes a diffstat of added/removed lines for each collected path
 156  * and requires passing an initialized got_diffstat_cb_arg argument.
 157  * The caller must allocate and initialize a got_pathlist_head * argument.
 158  * Data pointers of entries added to the path list will point to a struct
 159  * got_diff_changed_path object.
 160  * The caller is expected to free both the path and data pointers of all
 161  * entries on the path list.
 162  */
 163 struct got_diff_changed_path {
 164         uint32_t add;   /* number of lines added */
 165         uint32_t rm;    /* number of lines removed */
 166         /*
 167          * The modification status of this path. It can be GOT_STATUS_ADD,
 168          * GOT_STATUS_DELETE, GOT_STATUS_MODIFY, or GOT_STATUS_MODE_CHANGE.
 169          */
 170         int status;
 171 };
 172 const struct got_error *got_diff_tree_collect_changed_paths(void *,
 173     struct got_blob_object *, struct got_blob_object *, FILE *, FILE *,
 174     struct got_object_id *, struct got_object_id *,
 175     const char *, const char *, mode_t, mode_t, struct got_repository *);
 176
 177 struct got_diffstat_cb_arg {
 178         size_t max_path_len;
 179         uint32_t ins;
 180         uint32_t del;
 181         int add_cols;
 182         int rm_cols;
 183         int nfiles;
 184         struct got_pathlist_head *paths;
 185         int ignore_ws;
 186         int force_text;
 187         enum got_diff_algorithm diff_algo;
 188 };
 189 const struct got_error *got_diff_tree_compute_diffstat(void *,
 190     struct got_blob_object *, struct got_blob_object *, FILE *, FILE *,
 191     struct got_object_id *, struct got_object_id *, const char *, const char *,
 192     mode_t, mode_t, struct got_repository *);
 193
 194 /*
 195  * Diff two objects, assuming both objects are blobs. Two const char * diff
 196  * header labels may be provided which will be used to identify each blob in
 197  * the diff output. If a label is NULL, use the blob's hash instead.
 198  * Two open temporary files and two temporary file descriptors must be
 199  * provided for internal use; these files can be obtained from
 200  * got_opentemp() and got_opentempfd(), and must be closed by the caller.
 201  * The set of arguments relating to either blob may be NULL/-1 to indicate
 202  * that no content is present on its respective side of the diff.
 203  * The number of context lines to show in the diff must be specified as well.
 204  * Write unified diff text to the provided output FILE.
 205  * If not NULL, the two initial output arguments will be populated with an
 206  * array of line offsets for, and the number of lines in, the unidiff text.
 207  */
 208 const struct got_error *got_diff_objects_as_blobs(struct got_diff_line **,
 209     size_t *, FILE *, FILE *, int, int, struct got_object_id *,
 210     struct got_object_id *, const char *, const char *, enum got_diff_algorithm,
 211     int, int, int, struct got_diffstat_cb_arg *, struct got_repository *,
 212     FILE *);
 213
 214 struct got_pathlist_head;
 215
 216 /*
 217  * Diff two objects, assuming both objects are trees. Two const char * diff
 218  * header labels may be provided which will be used to identify each blob in
 219  * the trees. If a label is NULL, use the blob's hash instead.
 220  * The number of context lines to show in diffs must be specified.
 221  * Two open temporary files and two temporary file descriptors must be
 222  * provided for internal use; these files can be obtained from
 223  * got_opentemp() and got_opentempfd(), and must be closed by the caller.
 224  * If 'diff_content' is not set, the files may be NULL / -1.
 225  * The set of arguments relating to either tree may be NULL to indicate
 226  * that no content is present on its respective side of the diff.
 227  * Write unified diff text to the provided output FILE.
 228  * If not NULL, the two initial output arguments will be populated with an
 229  * array of line offsets for, and the number of lines in, the unidiff text.
 230  */
 231 const struct got_error *got_diff_objects_as_trees(struct got_diff_line **,
 232     size_t *, FILE *, FILE *, int, int, struct got_object_id *,
 233     struct got_object_id *, struct got_pathlist_head *, const char *,
 234     const char *, enum got_diff_algorithm, int, int, int,
 235     struct got_diffstat_cb_arg *, struct got_repository *, FILE *);
 236
 237 /*
 238  * Diff two objects, assuming both objects are commits.
 239  * The number of context lines to show in diffs must be specified.
 240  * Two open temporary files and two temporary file descriptors must be
 241  * provided for internal use; these files can be obtained from
 242  * got_opentemp() and got_opentempfd(), and must be closed by the caller.
 243  * The set of arguments relating to either commit may be NULL to indicate
 244  * that no content is present on its respective side of the diff.
 245  * Write unified diff text to the provided output FILE.
 246  * If not NULL, the two initial output arguments will be populated with an
 247  * array of line offsets for, and the number of lines in, the unidiff text.
 248  */
 249 const struct got_error *got_diff_objects_as_commits(struct got_diff_line **,
 250     size_t *, FILE *, FILE *, int, int, struct got_object_id *,
 251     struct got_object_id *, struct got_pathlist_head *, enum got_diff_algorithm,
 252     int, int, int, struct got_diffstat_cb_arg *, struct got_repository *,
 253     FILE *);
 254
 255 #define GOT_DIFF_MAX_CONTEXT    64