git/revision.h
Thomas Rast 12da1d1f6f Implement line-history search (git log -L)
This is a rewrite of much of Bo's work, mainly in an effort to split
it into smaller, easier to understand routines.

The algorithm is built around the struct range_set, which encodes a
series of line ranges as intervals [a,b).  This is used in two
contexts:

* A set of lines we are tracking (which will change as we dig through
  history).
* To encode diffs, as pairs of ranges.

The main routine is range_set_map_across_diff().  It processes the
diff between a commit C and some parent P.  It determines which diff
hunks are relevant to the ranges tracked in C, and computes the new
ranges for P.

The algorithm is then simply to process history in topological order
from newest to oldest, computing ranges and (partial) diffs.  At
branch points, we need to merge the ranges we are watching.  We will
find that many commits do not affect the chosen ranges, and mark them
TREESAME (in addition to those already filtered by pathspec limiting).
Another pass of history simplification then gets rid of such commits.

This is wired as an extra filtering pass in the log machinery.  This
currently only reduces code duplication, but should allow for other
simplifications and options to be used.

Finally, we hook a diff printer into the output chain.  Ideally we
would wire directly into the diff logic, to optionally use features
like word diff.  However, that will require some major reworking of
the diff chain, so we completely replace the output with our own diff
for now.

As this was a GSoC project, and has quite some history by now, many
people have helped.  In no particular order, thanks go to

  Jakub Narebski <jnareb@gmail.com>
  Jens Lehmann <Jens.Lehmann@web.de>
  Jonathan Nieder <jrnieder@gmail.com>
  Junio C Hamano <gitster@pobox.com>
  Ramsay Jones <ramsay@ramsay1.demon.co.uk>
  Will Palmer <wmpalmer@gmail.com>

Apologies to everyone I forgot.

Signed-off-by: Bo Yang <struggleyb.nku@gmail.com>
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-28 10:29:22 -07:00

259 lines
6.3 KiB
C

#ifndef REVISION_H
#define REVISION_H
#include "parse-options.h"
#include "grep.h"
#include "notes.h"
#define SEEN (1u<<0)
#define UNINTERESTING (1u<<1)
#define TREESAME (1u<<2)
#define SHOWN (1u<<3)
#define TMP_MARK (1u<<4) /* for isolated cases; clean after use */
#define BOUNDARY (1u<<5)
#define CHILD_SHOWN (1u<<6)
#define ADDED (1u<<7) /* Parents already parsed and added? */
#define SYMMETRIC_LEFT (1u<<8)
#define PATCHSAME (1u<<9)
#define ALL_REV_FLAGS ((1u<<10)-1)
#define DECORATE_SHORT_REFS 1
#define DECORATE_FULL_REFS 2
struct rev_info;
struct log_info;
struct string_list;
struct rev_cmdline_info {
unsigned int nr;
unsigned int alloc;
struct rev_cmdline_entry {
struct object *item;
const char *name;
enum {
REV_CMD_REF,
REV_CMD_PARENTS_ONLY,
REV_CMD_LEFT,
REV_CMD_RIGHT,
REV_CMD_REV
} whence;
unsigned flags;
} *rev;
};
#define REVISION_WALK_WALK 0
#define REVISION_WALK_NO_WALK_SORTED 1
#define REVISION_WALK_NO_WALK_UNSORTED 2
struct rev_info {
/* Starting list */
struct commit_list *commits;
struct object_array pending;
/* Parents of shown commits */
struct object_array boundary_commits;
/* The end-points specified by the end user */
struct rev_cmdline_info cmdline;
/* Basic information */
const char *prefix;
const char *def;
struct pathspec prune_data;
unsigned int early_output:1,
ignore_missing:1;
/* Traversal flags */
unsigned int dense:1,
prune:1,
no_walk:2,
show_all:1,
remove_empty_trees:1,
simplify_history:1,
lifo:1,
topo_order:1,
simplify_merges:1,
simplify_by_decoration:1,
tag_objects:1,
tree_objects:1,
blob_objects:1,
verify_objects:1,
edge_hint:1,
limited:1,
unpacked:1,
boundary:2,
count:1,
left_right:1,
left_only:1,
right_only:1,
rewrite_parents:1,
print_parents:1,
show_source:1,
show_decorations:1,
reverse:1,
reverse_output_stage:1,
cherry_pick:1,
cherry_mark:1,
bisect:1,
ancestry_path:1,
first_parent_only:1,
line_level_traverse:1;
/* Diff flags */
unsigned int diff:1,
full_diff:1,
show_root_diff:1,
no_commit_id:1,
verbose_header:1,
ignore_merges:1,
combine_merges:1,
dense_combined_merges:1,
always_show_header:1;
/* Format info */
unsigned int shown_one:1,
shown_dashes:1,
show_merge:1,
show_notes:1,
show_notes_given:1,
show_signature:1,
pretty_given:1,
abbrev_commit:1,
abbrev_commit_given:1,
use_terminator:1,
missing_newline:1,
date_mode_explicit:1,
preserve_subject:1;
unsigned int disable_stdin:1;
unsigned int leak_pending:1;
enum date_mode date_mode;
unsigned int abbrev;
enum cmit_fmt commit_format;
struct log_info *loginfo;
int nr, total;
const char *mime_boundary;
const char *patch_suffix;
int numbered_files;
int reroll_count;
char *message_id;
struct string_list *ref_message_ids;
const char *add_signoff;
const char *extra_headers;
const char *log_reencode;
const char *subject_prefix;
int no_inline;
int show_log_size;
struct string_list *mailmap;
/* Filter by commit log message */
struct grep_opt grep_filter;
/* Display history graph */
struct git_graph *graph;
/* special limits */
int skip_count;
int max_count;
unsigned long max_age;
unsigned long min_age;
int min_parents;
int max_parents;
/* diff info for patches and for paths limiting */
struct diff_options diffopt;
struct diff_options pruning;
struct reflog_walk_info *reflog_info;
struct decoration children;
struct decoration merge_simplification;
/* notes-specific options: which refs to show */
struct display_notes_opt notes_opt;
/* commit counts */
int count_left;
int count_right;
int count_same;
/* line level range that we are chasing */
struct decoration line_log_data;
};
#define REV_TREE_SAME 0
#define REV_TREE_NEW 1 /* Only new files */
#define REV_TREE_OLD 2 /* Only files removed */
#define REV_TREE_DIFFERENT 3 /* Mixed changes */
/* revision.c */
typedef void (*show_early_output_fn_t)(struct rev_info *, struct commit_list *);
extern volatile show_early_output_fn_t show_early_output;
struct setup_revision_opt {
const char *def;
void (*tweak)(struct rev_info *, struct setup_revision_opt *);
const char *submodule;
int assume_dashdash;
unsigned revarg_opt;
};
extern void init_revisions(struct rev_info *revs, const char *prefix);
extern int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *);
extern void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
const struct option *options,
const char * const usagestr[]);
#define REVARG_CANNOT_BE_FILENAME 01
#define REVARG_COMMITTISH 02
extern int handle_revision_arg(const char *arg, struct rev_info *revs, int flags, unsigned revarg_opt);
extern void reset_revision_walk(void);
extern int prepare_revision_walk(struct rev_info *revs);
extern struct commit *get_revision(struct rev_info *revs);
extern char *get_revision_mark(const struct rev_info *revs, const struct commit *commit);
extern void put_revision_mark(const struct rev_info *revs, const struct commit *commit);
extern void mark_parents_uninteresting(struct commit *commit);
extern void mark_tree_uninteresting(struct tree *tree);
struct name_path {
struct name_path *up;
int elem_len;
const char *elem;
};
char *path_name(const struct name_path *path, const char *name);
extern void show_object_with_name(FILE *, struct object *, const struct name_path *, const char *);
extern void add_object(struct object *obj,
struct object_array *p,
struct name_path *path,
const char *name);
extern void add_pending_object(struct rev_info *revs, struct object *obj, const char *name);
extern void add_pending_sha1(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags);
extern void add_head_to_pending(struct rev_info *);
enum commit_action {
commit_ignore,
commit_show,
commit_error
};
extern enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit);
extern enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit);
enum rewrite_result {
rewrite_one_ok,
rewrite_one_noparents,
rewrite_one_error
};
typedef enum rewrite_result (*rewrite_parent_fn_t)(struct rev_info *revs, struct commit **pp);
extern int rewrite_parents(struct rev_info *revs, struct commit *commit,
rewrite_parent_fn_t rewrite_parent);
#endif