git/diffcore.h
Elijah Newren f239fff4c1 merge-ort: store filepairs and filespecs in our mem_pool
For the testcases mentioned in commit 557ac0350d ("merge-ort: begin
performance work; instrument with trace2_region_* calls", 2020-10-28),
this change improves the performance as follows:

                            Before                  After
    no-renames:       198.1 ms ±  2.6 ms     198.5 ms ±  3.4 ms
    mega-renames:     715.8 ms ±  4.0 ms     679.1 ms ±  5.6 ms
    just-one-mega:    276.8 ms ±  4.2 ms     271.9 ms ±  2.8 ms

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-30 09:01:19 -07:00

235 lines
7.5 KiB
C

/*
* Copyright (C) 2005 Junio C Hamano
*/
#ifndef DIFFCORE_H
#define DIFFCORE_H
#include "cache.h"
struct diff_options;
struct repository;
struct strintmap;
struct strmap;
struct userdiff_driver;
/* 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.
*/
/* 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%) */
#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;
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 oid_valid : 1; /* if true, use oid 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 */
/* data should be considered "binary"; -1 means "don't know yet" */
signed int is_binary : 2;
struct userdiff_driver *driver;
};
struct diff_filespec *alloc_filespec(const char *);
void free_filespec(struct diff_filespec *);
void fill_filespec(struct diff_filespec *, const struct object_id *,
int, unsigned short);
/*
* Prefetch the entries in diff_queued_diff. The parameter is a pointer to a
* struct repository.
*/
void diff_queued_diff_prefetch(void *repository);
struct diff_populate_filespec_options {
unsigned check_size_only : 1;
unsigned check_binary : 1;
/*
* If an object is missing, diff_populate_filespec() will invoke this
* callback before attempting to read that object again.
*/
void (*missing_object_cb)(void *);
void *missing_object_data;
};
int diff_populate_filespec(struct repository *, struct diff_filespec *,
const struct diff_populate_filespec_options *);
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;
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)
void diff_free_filepair(struct diff_filepair *);
void pool_diff_free_filepair(struct mem_pool *pool,
struct diff_filepair *p);
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; \
(q)->nr = (q)->alloc = 0; \
} while (0)
extern struct diff_queue_struct diff_queued_diff;
struct diff_filepair *diff_queue(struct diff_queue_struct *,
struct diff_filespec *,
struct diff_filespec *);
void diff_q(struct diff_queue_struct *, struct diff_filepair *);
/* dir_rename_relevance: the reason we want rename information for a dir */
enum dir_rename_relevance {
NOT_RELEVANT = 0,
RELEVANT_FOR_ANCESTOR = 1,
RELEVANT_FOR_SELF = 2
};
/* file_rename_relevance: the reason(s) we want rename information for a file */
enum file_rename_relevance {
RELEVANT_NO_MORE = 0, /* i.e. NOT relevant */
RELEVANT_CONTENT = 1,
RELEVANT_LOCATION = 2
};
void partial_clear_dir_rename_count(struct strmap *dir_rename_count);
void diffcore_break(struct repository *, int);
void diffcore_rename(struct diff_options *);
void diffcore_rename_extended(struct diff_options *options,
struct mem_pool *pool,
struct strintmap *relevant_sources,
struct strintmap *dirs_removed,
struct strmap *dir_rename_count,
struct strmap *cached_pairs);
void diffcore_merge_broken(void);
void diffcore_pickaxe(struct diff_options *);
void diffcore_order(const char *orderfile);
void diffcore_rotate(struct diff_options *);
/* 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
int diffcore_count_changes(struct repository *r,
struct diff_filespec *src,
struct diff_filespec *dst,
void **src_count_p,
void **dst_count_p,
unsigned long *src_copied,
unsigned long *literal_added);
/*
* If filespec contains an OID and if that object is missing from the given
* repository, add that OID to to_fetch.
*/
void diff_add_if_missing(struct repository *r,
struct oid_array *to_fetch,
const struct diff_filespec *filespec);
#endif