mirror of
https://github.com/git/git
synced 2024-08-24 18:26:02 +00:00
![Jonathan Tan](/assets/img/avatar_default.png)
Commit 7fbbcb21b1
("diff: batch fetching of missing blobs", 2019-04-08)
optimized "diff" by prefetching blobs in a partial clone, but there are
some cases wherein blobs do not need to be prefetched. In these cases,
any command that uses the diff machinery will unnecessarily fetch blobs.
diffcore_std() may read blobs when it calls the following functions:
(1) diffcore_skip_stat_unmatch() (controlled by the config variable
diff.autorefreshindex)
(2) diffcore_break() and diffcore_merge_broken() (for break-rewrite
detection)
(3) diffcore_rename() (for rename detection)
(4) diffcore_pickaxe() (for detecting addition/deletion of specified
string)
Instead of always prefetching blobs, teach diffcore_skip_stat_unmatch(),
diffcore_break(), and diffcore_rename() to prefetch blobs upon the first
read of a missing object. This covers (1), (2), and (3): to cover the
rest, teach diffcore_std() to prefetch if the output type is one that
includes blob data (and hence blob data will be required later anyway),
or if it knows that (4) will be run.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
210 lines
6.6 KiB
C
210 lines
6.6 KiB
C
/*
|
|
* Copyright (C) 2005 Junio C Hamano
|
|
*/
|
|
#ifndef DIFFCORE_H
|
|
#define DIFFCORE_H
|
|
|
|
#include "cache.h"
|
|
|
|
struct diff_options;
|
|
struct repository;
|
|
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 *);
|
|
|
|
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 *);
|
|
|
|
void diffcore_break(struct repository *, int);
|
|
void diffcore_rename(struct diff_options *);
|
|
void diffcore_merge_broken(void);
|
|
void diffcore_pickaxe(struct diff_options *);
|
|
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
|
|
|
|
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
|