git/diffcore.h

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/*
* Copyright (C) 2005 Junio C Hamano
*/
#ifndef DIFFCORE_H
#define DIFFCORE_H
/* This header file is internal between diff.c and its diff transformers
* (e.g. diffcore-rename, diffcore-pickaxe). Never include this header
* in anything else.
*/
[PATCH] diff: Update -B heuristics. As Linus pointed out on the mailing list discussion, -B should break a files that has many inserts even if it still keeps enough of the original contents, so that the broken pieces can later be matched with other files by -M or -C. However, if such a broken pair does not get picked up by -M or -C, we would want to apply different criteria; namely, regardless of the amount of new material in the result, the determination of "rewrite" should be done by looking at the amount of original material still left in the result. If you still have the original 97 lines from a 100-line document, it does not matter if you add your own 13 lines to make a 110-line document, or if you add 903 lines to make a 1000-line document. It is not a rewrite but an in-place edit. On the other hand, if you did lose 97 lines from the original, it does not matter if you added 27 lines to make a 30-line document or if you added 997 lines to make a 1000-line document. You did a complete rewrite in either case. This patch introduces a post-processing phase that runs after diffcore-rename matches up broken pairs diffcore-break creates. The purpose of this post-processing is to pick up these broken pieces and merge them back into in-place modifications. For this, the score parameter -B option takes is changed into a pair of numbers, and it takes "-B99/80" format when fully spelled out. The first number is the minimum amount of "edit" (same definition as what diffcore-rename uses, which is "sum of deletion and insertion") that a modification needs to have to be broken, and the second number is the minimum amount of "delete" a surviving broken pair must have to avoid being merged back together. It can be abbreviated to "-B" to use default for both, "-B9" or "-B9/" to use 90% for "edit" but default (80%) for merge avoidance, or "-B/75" to use default (99%) "edit" and 75% for merge avoidance. Signed-off-by: Junio C Hamano <junkio@cox.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-03 08:40:28 +00:00
/* We internally use unsigned short as the score value,
* and rely on an int capable to hold 32-bits. -B can take
* -Bmerge_score/break_score format and the two scores are
* passed around in one int (high 16-bit for merge and low 16-bit
* for break).
*/
#define MAX_SCORE 60000.0
#define DEFAULT_RENAME_SCORE 30000 /* rename/copy similarity minimum (50%) */
#define DEFAULT_BREAK_SCORE 30000 /* minimum for break to happen (50%) */
#define DEFAULT_MERGE_SCORE 36000 /* maximum for break-merge to happen (60%) */
[PATCH] diff: Update -B heuristics. As Linus pointed out on the mailing list discussion, -B should break a files that has many inserts even if it still keeps enough of the original contents, so that the broken pieces can later be matched with other files by -M or -C. However, if such a broken pair does not get picked up by -M or -C, we would want to apply different criteria; namely, regardless of the amount of new material in the result, the determination of "rewrite" should be done by looking at the amount of original material still left in the result. If you still have the original 97 lines from a 100-line document, it does not matter if you add your own 13 lines to make a 110-line document, or if you add 903 lines to make a 1000-line document. It is not a rewrite but an in-place edit. On the other hand, if you did lose 97 lines from the original, it does not matter if you added 27 lines to make a 30-line document or if you added 997 lines to make a 1000-line document. You did a complete rewrite in either case. This patch introduces a post-processing phase that runs after diffcore-rename matches up broken pairs diffcore-break creates. The purpose of this post-processing is to pick up these broken pieces and merge them back into in-place modifications. For this, the score parameter -B option takes is changed into a pair of numbers, and it takes "-B99/80" format when fully spelled out. The first number is the minimum amount of "edit" (same definition as what diffcore-rename uses, which is "sum of deletion and insertion") that a modification needs to have to be broken, and the second number is the minimum amount of "delete" a surviving broken pair must have to avoid being merged back together. It can be abbreviated to "-B" to use default for both, "-B9" or "-B9/" to use 90% for "edit" but default (80%) for merge avoidance, or "-B/75" to use default (99%) "edit" and 75% for merge avoidance. Signed-off-by: Junio C Hamano <junkio@cox.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-03 08:40:28 +00:00
#define MINIMUM_BREAK_SIZE 400 /* do not break a file smaller than this */
diff: introduce diff.<driver>.binary The "diff" gitattribute is somewhat overloaded right now. It can say one of three things: 1. this file is definitely binary, or definitely not (i.e., diff or !diff) 2. this file should use an external diff engine (i.e., diff=foo, diff.foo.command = custom-script) 3. this file should use particular funcname patterns (i.e., diff=foo, diff.foo.(x?)funcname = some-regex) Most of the time, there is no conflict between these uses, since using one implies that the other is irrelevant (e.g., an external diff engine will decide for itself whether the file is binary). However, there is at least one conflicting situation: there is no way to say "use the regular rules to determine whether this file is binary, but if we do diff it textually, use this funcname pattern." That is, currently setting diff=foo indicates that the file is definitely text. This patch introduces a "binary" config option for a diff driver, so that one can explicitly set diff.foo.binary. We default this value to "don't know". That is, setting a diff attribute to "foo" and using "diff.foo.funcname" will have no effect on the binaryness of a file. To get the current behavior, one can set diff.foo.binary to true. This patch also has one additional advantage: it cleans up the interface to the userdiff code a bit. Before, calling code had to know more about whether attributes were false, true, or unset to determine binaryness. Now that binaryness is a property of a driver, we can represent these situations just by passing back a driver struct. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-10-05 21:43:36 +00:00
struct userdiff_driver;
struct diff_filespec {
unsigned char sha1[20];
char *path;
void *data;
void *cnt_data;
unsigned long size;
int count; /* Reference count */
int rename_used; /* Count of rename users */
unsigned short mode; /* file mode */
unsigned sha1_valid : 1; /* if true, use sha1 and trust mode;
* if false, use the name and read from
* the filesystem.
*/
#define DIFF_FILE_VALID(spec) (((spec)->mode) != 0)
unsigned should_free : 1; /* data should be free()'ed */
unsigned should_munmap : 1; /* data should be munmap()'ed */
unsigned dirty_submodule : 2; /* For submodules: its work tree is dirty */
#define DIRTY_SUBMODULE_UNTRACKED 1
#define DIRTY_SUBMODULE_MODIFIED 2
unsigned is_stdin : 1;
unsigned has_more_entries : 1; /* only appear in combined diff */
diff: introduce diff.<driver>.binary The "diff" gitattribute is somewhat overloaded right now. It can say one of three things: 1. this file is definitely binary, or definitely not (i.e., diff or !diff) 2. this file should use an external diff engine (i.e., diff=foo, diff.foo.command = custom-script) 3. this file should use particular funcname patterns (i.e., diff=foo, diff.foo.(x?)funcname = some-regex) Most of the time, there is no conflict between these uses, since using one implies that the other is irrelevant (e.g., an external diff engine will decide for itself whether the file is binary). However, there is at least one conflicting situation: there is no way to say "use the regular rules to determine whether this file is binary, but if we do diff it textually, use this funcname pattern." That is, currently setting diff=foo indicates that the file is definitely text. This patch introduces a "binary" config option for a diff driver, so that one can explicitly set diff.foo.binary. We default this value to "don't know". That is, setting a diff attribute to "foo" and using "diff.foo.funcname" will have no effect on the binaryness of a file. To get the current behavior, one can set diff.foo.binary to true. This patch also has one additional advantage: it cleans up the interface to the userdiff code a bit. Before, calling code had to know more about whether attributes were false, true, or unset to determine binaryness. Now that binaryness is a property of a driver, we can represent these situations just by passing back a driver struct. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-10-05 21:43:36 +00:00
/* data should be considered "binary"; -1 means "don't know yet" */
signed int is_binary : 2;
struct userdiff_driver *driver;
};
extern struct diff_filespec *alloc_filespec(const char *);
extern void free_filespec(struct diff_filespec *);
extern void fill_filespec(struct diff_filespec *, const unsigned char *,
diff: do not use null sha1 as a sentinel value The diff code represents paths using the diff_filespec struct. This struct has a sha1 to represent the sha1 of the content at that path, as well as a sha1_valid member which indicates whether its sha1 field is actually useful. If sha1_valid is not true, then the filespec represents a working tree file (e.g., for the no-index case, or for when the index is not up-to-date). The diff_filespec is only used internally, though. At the interfaces to the diff subsystem, callers feed the sha1 directly, and we create a diff_filespec from it. It's at that point that we look at the sha1 and decide whether it is valid or not; callers may pass the null sha1 as a sentinel value to indicate that it is not. We should not typically see the null sha1 coming from any other source (e.g., in the index itself, or from a tree). However, a corrupt tree might have a null sha1, which would cause "diff --patch" to accidentally diff the working tree version of a file instead of treating it as a blob. This patch extends the edges of the diff interface to accept a "sha1_valid" flag whenever we accept a sha1, and to use that flag when creating a filespec. In some cases, this means passing the flag through several layers, making the code change larger than would be desirable. One alternative would be to simply die() upon seeing corrupted trees with null sha1s. However, this fix more directly addresses the problem (while bogus sha1s in a tree are probably a bad thing, it is really the sentinel confusion sending us down the wrong code path that is what makes it devastating). And it means that git is more capable of examining and debugging these corrupted trees. For example, you can still "diff --raw" such a tree to find out when the bogus entry was introduced; you just cannot do a "--patch" diff (just as you could not with any other corrupted tree, as we do not have any content to diff). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-07-28 15:03:01 +00:00
int, unsigned short);
extern int diff_populate_filespec(struct diff_filespec *, int);
extern void diff_free_filespec_data(struct diff_filespec *);
extern void diff_free_filespec_blob(struct diff_filespec *);
extern int diff_filespec_is_binary(struct diff_filespec *);
struct diff_filepair {
struct diff_filespec *one;
struct diff_filespec *two;
unsigned short int score;
char status; /* M C R A D U etc. (see Documentation/diff-format.txt or DIFF_STATUS_* in diff.h) */
unsigned broken_pair : 1;
unsigned renamed_pair : 1;
unsigned is_unmerged : 1;
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)
#define DIFF_PAIR_BROKEN(p) \
( (!DIFF_FILE_VALID((p)->one) != !DIFF_FILE_VALID((p)->two)) && \
((p)->broken_pair != 0) )
#define DIFF_PAIR_TYPE_CHANGED(p) \
((S_IFMT & (p)->one->mode) != (S_IFMT & (p)->two->mode))
#define DIFF_PAIR_MODE_CHANGED(p) ((p)->one->mode != (p)->two->mode)
extern void diff_free_filepair(struct diff_filepair *);
[PATCH] Rename/copy detection fix. The rename/copy detection logic in earlier round was only good enough to show patch output and discussion on the mailing list about the diff-raw format updates revealed many problems with it. This patch fixes all the ones known to me, without making things I want to do later impossible, mostly related to patch reordering. (1) Earlier rename/copy detector determined which one is rename and which one is copy too early, which made it impossible to later introduce diffcore transformers to reorder patches. This patch fixes it by moving that logic to the very end of the processing. (2) Earlier output routine diff_flush() was pruning all the "no-change" entries indiscriminatingly. This was done due to my false assumption that one of the requirements in the diff-raw output was not to show such an entry (which resulted in my incorrect comment about "diff-helper never being able to be equivalent to built-in diff driver"). My special thanks go to Linus for correcting me about this. When we produce diff-raw output, for the downstream to be able to tell renames from copies, sometimes it _is_ necessary to output "no-change" entries, and this patch adds diffcore_prune() function for doing it. (3) Earlier diff_filepair structure was trying to be not too specific about rename/copy operations, but the purpose of the structure was to record one or two paths, which _was_ indeed about rename/copy. This patch discards xfrm_msg field which was trying to be generic for this wrong reason, and introduces a couple of fields (rename_score and rename_rank) that are explicitly specific to rename/copy logic. One thing to note is that the information in a single diff_filepair structure _still_ does not distinguish renames from copies, and it is deliberately so. This is to allow patches to be reordered in later stages. (4) This patch also adds some tests about diff-raw format output and makes sure that necessary "no-change" entries appear on the output. Signed-off-by: Junio C Hamano <junkio@cox.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-23 04:26:09 +00:00
extern int diff_unmodified_pair(struct diff_filepair *);
struct diff_queue_struct {
struct diff_filepair **queue;
int alloc;
int nr;
};
#define DIFF_QUEUE_CLEAR(q) \
do { \
(q)->queue = NULL; \
(q)->nr = (q)->alloc = 0; \
} while (0)
extern struct diff_queue_struct diff_queued_diff;
extern struct diff_filepair *diff_queue(struct diff_queue_struct *,
struct diff_filespec *,
struct diff_filespec *);
extern void diff_q(struct diff_queue_struct *, struct diff_filepair *);
[PATCH] Rename/copy detection fix. The rename/copy detection logic in earlier round was only good enough to show patch output and discussion on the mailing list about the diff-raw format updates revealed many problems with it. This patch fixes all the ones known to me, without making things I want to do later impossible, mostly related to patch reordering. (1) Earlier rename/copy detector determined which one is rename and which one is copy too early, which made it impossible to later introduce diffcore transformers to reorder patches. This patch fixes it by moving that logic to the very end of the processing. (2) Earlier output routine diff_flush() was pruning all the "no-change" entries indiscriminatingly. This was done due to my false assumption that one of the requirements in the diff-raw output was not to show such an entry (which resulted in my incorrect comment about "diff-helper never being able to be equivalent to built-in diff driver"). My special thanks go to Linus for correcting me about this. When we produce diff-raw output, for the downstream to be able to tell renames from copies, sometimes it _is_ necessary to output "no-change" entries, and this patch adds diffcore_prune() function for doing it. (3) Earlier diff_filepair structure was trying to be not too specific about rename/copy operations, but the purpose of the structure was to record one or two paths, which _was_ indeed about rename/copy. This patch discards xfrm_msg field which was trying to be generic for this wrong reason, and introduces a couple of fields (rename_score and rename_rank) that are explicitly specific to rename/copy logic. One thing to note is that the information in a single diff_filepair structure _still_ does not distinguish renames from copies, and it is deliberately so. This is to allow patches to be reordered in later stages. (4) This patch also adds some tests about diff-raw format output and makes sure that necessary "no-change" entries appear on the output. Signed-off-by: Junio C Hamano <junkio@cox.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-23 04:26:09 +00:00
extern void diffcore_break(int);
extern void diffcore_rename(struct diff_options *);
[PATCH] diff: Update -B heuristics. As Linus pointed out on the mailing list discussion, -B should break a files that has many inserts even if it still keeps enough of the original contents, so that the broken pieces can later be matched with other files by -M or -C. However, if such a broken pair does not get picked up by -M or -C, we would want to apply different criteria; namely, regardless of the amount of new material in the result, the determination of "rewrite" should be done by looking at the amount of original material still left in the result. If you still have the original 97 lines from a 100-line document, it does not matter if you add your own 13 lines to make a 110-line document, or if you add 903 lines to make a 1000-line document. It is not a rewrite but an in-place edit. On the other hand, if you did lose 97 lines from the original, it does not matter if you added 27 lines to make a 30-line document or if you added 997 lines to make a 1000-line document. You did a complete rewrite in either case. This patch introduces a post-processing phase that runs after diffcore-rename matches up broken pairs diffcore-break creates. The purpose of this post-processing is to pick up these broken pieces and merge them back into in-place modifications. For this, the score parameter -B option takes is changed into a pair of numbers, and it takes "-B99/80" format when fully spelled out. The first number is the minimum amount of "edit" (same definition as what diffcore-rename uses, which is "sum of deletion and insertion") that a modification needs to have to be broken, and the second number is the minimum amount of "delete" a surviving broken pair must have to avoid being merged back together. It can be abbreviated to "-B" to use default for both, "-B9" or "-B9/" to use 90% for "edit" but default (80%) for merge avoidance, or "-B/75" to use default (99%) "edit" and 75% for merge avoidance. Signed-off-by: Junio C Hamano <junkio@cox.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-03 08:40:28 +00:00
extern void diffcore_merge_broken(void);
extern void diffcore_pickaxe(struct diff_options *);
extern void diffcore_order(const char *orderfile);
/* low-level interface to diffcore_order */
struct obj_order {
void *obj; /* setup by caller */
/* setup/used by order_objects() */
int orig_order;
int order;
};
typedef const char *(*obj_path_fn_t)(void *obj);
void order_objects(const char *orderfile, obj_path_fn_t obj_path,
struct obj_order *objs, int nr);
#define DIFF_DEBUG 0
#if DIFF_DEBUG
void diff_debug_filespec(struct diff_filespec *, int, const char *);
void diff_debug_filepair(const struct diff_filepair *, int);
void diff_debug_queue(const char *, struct diff_queue_struct *);
#else
#define diff_debug_filespec(a,b,c) do { /* nothing */ } while (0)
#define diff_debug_filepair(a,b) do { /* nothing */ } while (0)
#define diff_debug_queue(a,b) do { /* nothing */ } while (0)
#endif
extern int diffcore_count_changes(struct diff_filespec *src,
struct diff_filespec *dst,
void **src_count_p,
void **dst_count_p,
unsigned long delta_limit,
unsigned long *src_copied,
unsigned long *literal_added);
#endif