diff options
| -rw-r--r-- | Documentation/technical/api-diff.txt | 174 | ||||
| -rw-r--r-- | diff.h | 126 | ||||
| -rw-r--r-- | diffcore.h | 32 |
3 files changed, 158 insertions, 174 deletions
diff --git a/Documentation/technical/api-diff.txt b/Documentation/technical/api-diff.txt deleted file mode 100644 index 30fc0e9c93..0000000000 --- a/Documentation/technical/api-diff.txt +++ /dev/null @@ -1,174 +0,0 @@ -diff API -======== - -The diff API is for programs that compare two sets of files (e.g. two -trees, one tree and the index) and present the found difference in -various ways. The calling program is responsible for feeding the API -pairs of files, one from the "old" set and the corresponding one from -"new" set, that are different. The library called through this API is -called diffcore, and is responsible for two things. - -* finding total rewrites (`-B`), renames (`-M`) and copies (`-C`), and - changes that touch a string (`-S`), as specified by the caller. - -* outputting the differences in various formats, as specified by the - caller. - -Calling sequence ----------------- - -* Prepare `struct diff_options` to record the set of diff options, and - then call `repo_diff_setup()` to initialize this structure. This - sets up the vanilla default. - -* Fill in the options structure to specify desired output format, rename - detection, etc. `diff_opt_parse()` can be used to parse options given - from the command line in a way consistent with existing git-diff - family of programs. - -* Call `diff_setup_done()`; this inspects the options set up so far for - internal consistency and make necessary tweaking to it (e.g. if - textual patch output was asked, recursive behaviour is turned on); - the callback set_default in diff_options can be used to tweak this more. - -* As you find different pairs of files, call `diff_change()` to feed - modified files, `diff_addremove()` to feed created or deleted files, - or `diff_unmerge()` to feed a file whose state is 'unmerged' to the - API. These are thin wrappers to a lower-level `diff_queue()` function - that is flexible enough to record any of these kinds of changes. - -* Once you finish feeding the pairs of files, call `diffcore_std()`. - This will tell the diffcore library to go ahead and do its work. - -* Calling `diff_flush()` will produce the output. - - -Data structures ---------------- - -* `struct diff_filespec` - -This is the internal representation for a single file (blob). It -records the blob object name (if known -- for a work tree file it -typically is a NUL SHA-1), filemode and pathname. This is what the -`diff_addremove()`, `diff_change()` and `diff_unmerge()` synthesize and -feed `diff_queue()` function with. - -* `struct diff_filepair` - -This records a pair of `struct diff_filespec`; the filespec for a file -in the "old" set (i.e. preimage) is called `one`, and the filespec for a -file in the "new" set (i.e. postimage) is called `two`. A change that -represents file creation has NULL in `one`, and file deletion has NULL -in `two`. - -A `filepair` starts pointing at `one` and `two` that are from the same -filename, but `diffcore_std()` can break pairs and match component -filespecs with other filespecs from a different filepair to form new -filepair. This is called 'rename detection'. - -* `struct diff_queue` - -This is a collection of filepairs. Notable members are: - -`queue`:: - - An array of pointers to `struct diff_filepair`. This - dynamically grows as you add filepairs; - -`alloc`:: - - The allocated size of the `queue` array; - -`nr`:: - - The number of elements in the `queue` array. - - -* `struct diff_options` - -This describes the set of options the calling program wants to affect -the operation of diffcore library with. - -Notable members are: - -`output_format`:: - The output format used when `diff_flush()` is run. - -`context`:: - Number of context lines to generate in patch output. - -`break_opt`, `detect_rename`, `rename-score`, `rename_limit`:: - Affects the way detection logic for complete rewrites, renames - and copies. - -`abbrev`:: - Number of hexdigits to abbreviate raw format output to. - -`pickaxe`:: - A constant string (can and typically does contain newlines to - look for a block of text, not just a single line) to filter out - the filepairs that do not change the number of strings contained - in its preimage and postimage of the diff_queue. - -`flags`:: - This is mostly a collection of boolean options that affects the - operation, but some do not have anything to do with the diffcore - library. - -`touched_flags`:: - Records whether a flag has been changed due to user request - (rather than just set/unset by default). - -`set_default`:: - Callback which allows tweaking the options in diff_setup_done(). - -BINARY, TEXT;; - Affects the way how a file that is seemingly binary is treated. - -FULL_INDEX;; - Tells the patch output format not to use abbreviated object - names on the "index" lines. - -FIND_COPIES_HARDER;; - Tells the diffcore library that the caller is feeding unchanged - filepairs to allow copies from unmodified files be detected. - -COLOR_DIFF;; - Output should be colored. - -COLOR_DIFF_WORDS;; - Output is a colored word-diff. - -NO_INDEX;; - Tells diff-files that the input is not tracked files but files - in random locations on the filesystem. - -ALLOW_EXTERNAL;; - Tells output routine that it is Ok to call user specified patch - output routine. Plumbing disables this to ensure stable output. - -QUIET;; - Do not show any output. - -REVERSE_DIFF;; - Tells the library that the calling program is feeding the - filepairs reversed; `one` is two, and `two` is one. - -EXIT_WITH_STATUS;; - For communication between the calling program and the options - parser; tell the calling program to signal the presence of - difference using program exit code. - -HAS_CHANGES;; - Internal; used for optimization to see if there is any change. - -SILENT_ON_REMOVE;; - Affects if diff-files shows removed files. - -RECURSIVE, TREE_IN_RECURSIVE;; - Tells if tree traversal done by tree-diff should recursively - descend into a tree object pair that are different in preimage - and postimage set. - -(JC) @@ -9,6 +9,49 @@ #include "object.h" #include "oidset.h" +/** + * The diff API is for programs that compare two sets of files (e.g. two trees, + * one tree and the index) and present the found difference in various ways. + * The calling program is responsible for feeding the API pairs of files, one + * from the "old" set and the corresponding one from "new" set, that are + * different. + * The library called through this API is called diffcore, and is responsible + * for two things. + * + * - finding total rewrites (`-B`), renames (`-M`) and copies (`-C`), and + * changes that touch a string (`-S`), as specified by the caller. + * + * - outputting the differences in various formats, as specified by the caller. + * + * Calling sequence + * ---------------- + * + * - Prepare `struct diff_options` to record the set of diff options, and then + * call `repo_diff_setup()` to initialize this structure. This sets up the + * vanilla default. + * + * - Fill in the options structure to specify desired output format, rename + * detection, etc. `diff_opt_parse()` can be used to parse options given + * from the command line in a way consistent with existing git-diff family + * of programs. + * + * - Call `diff_setup_done()`; this inspects the options set up so far for + * internal consistency and make necessary tweaking to it (e.g. if textual + * patch output was asked, recursive behaviour is turned on); the callback + * set_default in diff_options can be used to tweak this more. + * + * - As you find different pairs of files, call `diff_change()` to feed + * modified files, `diff_addremove()` to feed created or deleted files, or + * `diff_unmerge()` to feed a file whose state is 'unmerged' to the API. + * These are thin wrappers to a lower-level `diff_queue()` function that is + * flexible enough to record any of these kinds of changes. + * + * - Once you finish feeding the pairs of files, call `diffcore_std()`. + * This will tell the diffcore library to go ahead and do its work. + * + * - Calling `diff_flush()` will produce the output. + */ + struct combine_diff_path; struct commit; struct diff_filespec; @@ -65,21 +108,66 @@ typedef struct strbuf *(*diff_prefix_fn_t)(struct diff_options *opt, void *data) #define DIFF_FLAGS_INIT { 0 } struct diff_flags { + + /** + * Tells if tree traversal done by tree-diff should recursively descend + * into a tree object pair that are different in preimage and postimage set. + */ unsigned recursive; unsigned tree_in_recursive; + + /* Affects the way how a file that is seemingly binary is treated. */ unsigned binary; unsigned text; + + /** + * Tells the patch output format not to use abbreviated object names on the + * "index" lines. + */ unsigned full_index; + + /* Affects if diff-files shows removed files. */ unsigned silent_on_remove; + + /** + * Tells the diffcore library that the caller is feeding unchanged + * filepairs to allow copies from unmodified files be detected. + */ unsigned find_copies_harder; + unsigned follow_renames; unsigned rename_empty; + + /* Internal; used for optimization to see if there is any change. */ unsigned has_changes; + unsigned quick; + + /** + * Tells diff-files that the input is not tracked files but files in random + * locations on the filesystem. + */ unsigned no_index; + + /** + * Tells output routine that it is Ok to call user specified patch output + * routine. Plumbing disables this to ensure stable output. + */ unsigned allow_external; + + /** + * For communication between the calling program and the options parser; + * tell the calling program to signal the presence of difference using + * program exit code. + */ unsigned exit_with_status; + + /** + * Tells the library that the calling program is feeding the filepairs + * reversed; `one` is two, and `two` is one. + */ unsigned reverse_diff; + unsigned check_failed; unsigned relative_name; unsigned ignore_submodules; @@ -131,36 +219,72 @@ enum diff_submodule_format { DIFF_SUBMODULE_INLINE_DIFF }; +/** + * the set of options the calling program wants to affect the operation of + * diffcore library with. + */ struct diff_options { const char *orderfile; + + /** + * A constant string (can and typically does contain newlines to look for + * a block of text, not just a single line) to filter out the filepairs + * that do not change the number of strings contained in its preimage and + * postimage of the diff_queue. + */ const char *pickaxe; + const char *single_follow; const char *a_prefix, *b_prefix; const char *line_prefix; size_t line_prefix_length; + + /** + * collection of boolean options that affects the operation, but some do + * not have anything to do with the diffcore library. + */ struct diff_flags flags; /* diff-filter bits */ unsigned int filter; int use_color; + + /* Number of context lines to generate in patch output. */ int context; + int interhunkcontext; + + /* Affects the way detection logic for complete rewrites, renames and + * copies. + */ int break_opt; int detect_rename; + int irreversible_delete; int skip_stat_unmatch; int line_termination; + + /* The output format used when `diff_flush()` is run. */ int output_format; + unsigned pickaxe_opts; + + /* Affects the way detection logic for complete rewrites, renames and + * copies. + */ int rename_score; int rename_limit; + int needed_rename_limit; int degraded_cc_to_c; int show_rename_progress; int dirstat_permille; int setup; + + /* Number of hexdigits to abbreviate raw format output to. */ int abbrev; + int ita_invisible_in_index; /* white-space error highlighting */ #define WSEH_NEW (1<<12) @@ -192,6 +316,7 @@ struct diff_options { /* to support internal diff recursion by --follow hack*/ int found_follow; + /* Callback which allows tweaking the options in diff_setup_done(). */ void (*set_default)(struct diff_options *); FILE *file; @@ -270,6 +395,7 @@ enum color_diff { DIFF_FILE_OLD_BOLD = 21, DIFF_FILE_NEW_BOLD = 22, }; + const char *diff_get_color(int diff_use_color, enum color_diff ix); #define diff_get_color_opt(o, ix) \ diff_get_color((o)->use_color, ix) diff --git a/diffcore.h b/diffcore.h index b651061c0e..7c07347e42 100644 --- a/diffcore.h +++ b/diffcore.h @@ -28,6 +28,12 @@ struct userdiff_driver; #define MINIMUM_BREAK_SIZE 400 /* do not break a file smaller than this */ +/** + * the internal representation for a single file (blob). It records the blob + * object name (if known -- for a work tree file it typically is a NUL SHA-1), + * filemode and pathname. This is what the `diff_addremove()`, `diff_change()` + * and `diff_unmerge()` synthesize and feed `diff_queue()` function with. + */ struct diff_filespec { struct object_id oid; char *path; @@ -66,6 +72,17 @@ void diff_free_filespec_data(struct diff_filespec *); void diff_free_filespec_blob(struct diff_filespec *); int diff_filespec_is_binary(struct repository *, struct diff_filespec *); +/** + * This records a pair of `struct diff_filespec`; the filespec for a file in + * the "old" set (i.e. preimage) is called `one`, and the filespec for a file + * in the "new" set (i.e. postimage) is called `two`. A change that represents + * file creation has NULL in `one`, and file deletion has NULL in `two`. + * + * A `filepair` starts pointing at `one` and `two` that are from the same + * filename, but `diffcore_std()` can break pairs and match component filespecs + * with other filespecs from a different filepair to form new filepair. This is + * called 'rename detection'. + */ struct diff_filepair { struct diff_filespec *one; struct diff_filespec *two; @@ -77,6 +94,7 @@ struct diff_filepair { unsigned done_skip_stat_unmatch : 1; unsigned skip_stat_unmatch_result : 1; }; + #define DIFF_PAIR_UNMERGED(p) ((p)->is_unmerged) #define DIFF_PAIR_RENAME(p) ((p)->renamed_pair) @@ -94,11 +112,25 @@ void diff_free_filepair(struct diff_filepair *); int diff_unmodified_pair(struct diff_filepair *); +/** + * This is a collection of filepairs. Notable members are: + * + * - `queue`: + * An array of pointers to `struct diff_filepair`. This dynamically grows as + * you add filepairs; + * + * - `alloc`: + * The allocated size of the `queue` array; + * + * - `nr`: + * The number of elements in the `queue` array. + */ struct diff_queue_struct { struct diff_filepair **queue; int alloc; int nr; }; + #define DIFF_QUEUE_CLEAR(q) \ do { \ (q)->queue = NULL; \ |