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Merge branch 'ks/tree-diff-nway'

Instead of running N pair-wise diff-trees when inspecting a
N-parent merge, find the set of paths that were touched by walking
N+1 trees in parallel.  These set of paths can then be turned into
N pair-wise diff-tree results to be processed through rename
detections and such.  And N=2 case nicely degenerates to the usual
2-way diff-tree, which is very nice.

* ks/tree-diff-nway:
  mingw: activate alloca
  combine-diff: speed it up, by using multiparent diff tree-walker directly
  tree-diff: rework diff_tree() to generate diffs for multiparent cases as well
  Portable alloca for Git
  tree-diff: reuse base str(buf) memory on sub-tree recursion
  tree-diff: no need to call "full" diff_tree_sha1 from show_path()
  tree-diff: rework diff_tree interface to be sha1 based
  tree-diff: diff_tree() should now be static
  tree-diff: remove special-case diff-emitting code for empty-tree cases
  tree-diff: simplify tree_entry_pathcmp
  tree-diff: show_path prototype is not needed anymore
  tree-diff: rename compare_tree_entry -> tree_entry_pathcmp
  tree-diff: move all action-taking code out of compare_tree_entry()
  tree-diff: don't assume compare_tree_entry() returns -1,0,1
  tree-diff: consolidate code for emitting diffs and recursion in one place
  tree-diff: show_tree() is not needed
  tree-diff: no need to pass match to skip_uninteresting()
  tree-diff: no need to manually verify that there is no mode change for a path
  combine-diff: move changed-paths scanning logic into its own function
  combine-diff: move show_log_first logic/action out of paths scanning
This commit is contained in:
Junio C Hamano 2014-06-03 12:06:40 -07:00
commit 8eaf517835
10 changed files with 728 additions and 175 deletions

View File

@ -30,6 +30,8 @@ all::
# Define LIBPCREDIR=/foo/bar if your libpcre header and library files are in
# /foo/bar/include and /foo/bar/lib directories.
#
# Define HAVE_ALLOCA_H if you have working alloca(3) defined in that header.
#
# Define NO_CURL if you do not have libcurl installed. git-http-fetch and
# git-http-push are not built, and you cannot use http:// and https://
# transports (neither smart nor dumb).
@ -1111,6 +1113,10 @@ ifdef USE_LIBPCRE
EXTLIBS += -lpcre
endif
ifdef HAVE_ALLOCA_H
BASIC_CFLAGS += -DHAVE_ALLOCA_H
endif
ifdef NO_CURL
BASIC_CFLAGS += -DNO_CURL
REMOTE_CURL_PRIMARY =

15
cache.h
View File

@ -74,6 +74,21 @@ unsigned long git_deflate_bound(git_zstream *, unsigned long);
#define S_IFGITLINK 0160000
#define S_ISGITLINK(m) (((m) & S_IFMT) == S_IFGITLINK)
/*
* Some mode bits are also used internally for computations.
*
* They *must* not overlap with any valid modes, and they *must* not be emitted
* to outside world - i.e. appear on disk or network. In other words, it's just
* temporary fields, which we internally use, but they have to stay in-house.
*
* ( such approach is valid, as standard S_IF* fits into 16 bits, and in Git
* codebase mode is `unsigned int` which is assumed to be at least 32 bits )
*/
/* used internally in tree-diff */
#define S_DIFFTREE_IFXMIN_NEQ 0x80000000
/*
* Intensive research over the course of many years has shown that
* port 9418 is totally unused by anything else. Or

View File

@ -1301,6 +1301,81 @@ static const char *path_path(void *obj)
return path->path;
}
/* find set of paths that every parent touches */
static struct combine_diff_path *find_paths_generic(const unsigned char *sha1,
const struct sha1_array *parents, struct diff_options *opt)
{
struct combine_diff_path *paths = NULL;
int i, num_parent = parents->nr;
int output_format = opt->output_format;
const char *orderfile = opt->orderfile;
opt->output_format = DIFF_FORMAT_NO_OUTPUT;
/* tell diff_tree to emit paths in sorted (=tree) order */
opt->orderfile = NULL;
/* D(A,P1...Pn) = D(A,P1) ^ ... ^ D(A,Pn) (wrt paths) */
for (i = 0; i < num_parent; i++) {
/*
* show stat against the first parent even when doing
* combined diff.
*/
int stat_opt = (output_format &
(DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
if (i == 0 && stat_opt)
opt->output_format = stat_opt;
else
opt->output_format = DIFF_FORMAT_NO_OUTPUT;
diff_tree_sha1(parents->sha1[i], sha1, "", opt);
diffcore_std(opt);
paths = intersect_paths(paths, i, num_parent);
/* if showing diff, show it in requested order */
if (opt->output_format != DIFF_FORMAT_NO_OUTPUT &&
orderfile) {
diffcore_order(orderfile);
}
diff_flush(opt);
}
opt->output_format = output_format;
opt->orderfile = orderfile;
return paths;
}
/*
* find set of paths that everybody touches, assuming diff is run without
* rename/copy detection, etc, comparing all trees simultaneously (= faster).
*/
static struct combine_diff_path *find_paths_multitree(
const unsigned char *sha1, const struct sha1_array *parents,
struct diff_options *opt)
{
int i, nparent = parents->nr;
const unsigned char **parents_sha1;
struct combine_diff_path paths_head;
struct strbuf base;
parents_sha1 = xmalloc(nparent * sizeof(parents_sha1[0]));
for (i = 0; i < nparent; i++)
parents_sha1[i] = parents->sha1[i];
/* fake list head, so worker can assume it is non-NULL */
paths_head.next = NULL;
strbuf_init(&base, PATH_MAX);
diff_tree_paths(&paths_head, sha1, parents_sha1, nparent, &base, opt);
strbuf_release(&base);
free(parents_sha1);
return paths_head.next;
}
void diff_tree_combined(const unsigned char *sha1,
const struct sha1_array *parents,
int dense,
@ -1308,49 +1383,82 @@ void diff_tree_combined(const unsigned char *sha1,
{
struct diff_options *opt = &rev->diffopt;
struct diff_options diffopts;
struct combine_diff_path *p, *paths = NULL;
struct combine_diff_path *p, *paths;
int i, num_paths, needsep, show_log_first, num_parent = parents->nr;
int need_generic_pathscan;
diffopts = *opt;
copy_pathspec(&diffopts.pathspec, &opt->pathspec);
diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
DIFF_OPT_SET(&diffopts, RECURSIVE);
DIFF_OPT_CLR(&diffopts, ALLOW_EXTERNAL);
/* tell diff_tree to emit paths in sorted (=tree) order */
diffopts.orderfile = NULL;
/* nothing to do, if no parents */
if (!num_parent)
return;
show_log_first = !!rev->loginfo && !rev->no_commit_id;
needsep = 0;
/* find set of paths that everybody touches */
for (i = 0; i < num_parent; i++) {
/* show stat against the first parent even
if (show_log_first) {
show_log(rev);
if (rev->verbose_header && opt->output_format)
printf("%s%c", diff_line_prefix(opt),
opt->line_termination);
}
diffopts = *opt;
copy_pathspec(&diffopts.pathspec, &opt->pathspec);
DIFF_OPT_SET(&diffopts, RECURSIVE);
DIFF_OPT_CLR(&diffopts, ALLOW_EXTERNAL);
/* find set of paths that everybody touches
*
* NOTE
*
* Diffcore transformations are bound to diff_filespec and logic
* comparing two entries - i.e. they do not apply directly to combine
* diff.
*
* If some of such transformations is requested - we launch generic
* path scanning, which works significantly slower compared to
* simultaneous all-trees-in-one-go scan in find_paths_multitree().
*
* TODO some of the filters could be ported to work on
* combine_diff_paths - i.e. all functionality that skips paths, so in
* theory, we could end up having only multitree path scanning.
*
* NOTE please keep this semantically in sync with diffcore_std()
*/
need_generic_pathscan = opt->skip_stat_unmatch ||
DIFF_OPT_TST(opt, FOLLOW_RENAMES) ||
opt->break_opt != -1 ||
opt->detect_rename ||
opt->pickaxe ||
opt->filter;
if (need_generic_pathscan) {
/*
* NOTE generic case also handles --stat, as it computes
* diff(sha1,parent_i) for all i to do the job, specifically
* for parent0.
*/
paths = find_paths_generic(sha1, parents, &diffopts);
}
else {
int stat_opt;
paths = find_paths_multitree(sha1, parents, &diffopts);
/*
* show stat against the first parent even
* when doing combined diff.
*/
int stat_opt = (opt->output_format &
stat_opt = (opt->output_format &
(DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
if (i == 0 && stat_opt)
if (stat_opt) {
diffopts.output_format = stat_opt;
else
diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
diff_tree_sha1(parents->sha1[i], sha1, "", &diffopts);
diffcore_std(&diffopts);
paths = intersect_paths(paths, i, num_parent);
if (show_log_first && i == 0) {
show_log(rev);
if (rev->verbose_header && opt->output_format)
printf("%s%c", diff_line_prefix(opt),
opt->line_termination);
diff_tree_sha1(parents->sha1[0], sha1, "", &diffopts);
diffcore_std(&diffopts);
if (opt->orderfile)
diffcore_order(opt->orderfile);
diff_flush(&diffopts);
}
/* if showing diff, show it in requested order */
if (diffopts.output_format != DIFF_FORMAT_NO_OUTPUT &&
opt->orderfile) {
diffcore_order(opt->orderfile);
}
diff_flush(&diffopts);
}
/* find out number of surviving paths */

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@ -28,6 +28,7 @@ ifeq ($(uname_S),OSF1)
NO_NSEC = YesPlease
endif
ifeq ($(uname_S),Linux)
HAVE_ALLOCA_H = YesPlease
NO_STRLCPY = YesPlease
NO_MKSTEMPS = YesPlease
HAVE_PATHS_H = YesPlease
@ -35,6 +36,7 @@ ifeq ($(uname_S),Linux)
HAVE_DEV_TTY = YesPlease
endif
ifeq ($(uname_S),GNU/kFreeBSD)
HAVE_ALLOCA_H = YesPlease
NO_STRLCPY = YesPlease
NO_MKSTEMPS = YesPlease
HAVE_PATHS_H = YesPlease
@ -103,6 +105,7 @@ ifeq ($(uname_S),SunOS)
NEEDS_NSL = YesPlease
SHELL_PATH = /bin/bash
SANE_TOOL_PATH = /usr/xpg6/bin:/usr/xpg4/bin
HAVE_ALLOCA_H = YesPlease
NO_STRCASESTR = YesPlease
NO_MEMMEM = YesPlease
NO_MKDTEMP = YesPlease
@ -145,7 +148,7 @@ ifeq ($(uname_S),SunOS)
endif
INSTALL = /usr/ucb/install
TAR = gtar
BASIC_CFLAGS += -D__EXTENSIONS__ -D__sun__ -DHAVE_ALLOCA_H
BASIC_CFLAGS += -D__EXTENSIONS__ -D__sun__
endif
ifeq ($(uname_O),Cygwin)
ifeq ($(shell expr "$(uname_R)" : '1\.[1-6]\.'),4)
@ -165,6 +168,7 @@ ifeq ($(uname_O),Cygwin)
else
NO_REGEX = UnfortunatelyYes
endif
HAVE_ALLOCA_H = YesPlease
NEEDS_LIBICONV = YesPlease
NO_FAST_WORKING_DIRECTORY = UnfortunatelyYes
NO_ST_BLOCKS_IN_STRUCT_STAT = YesPlease
@ -239,6 +243,7 @@ ifeq ($(uname_S),AIX)
endif
ifeq ($(uname_S),GNU)
# GNU/Hurd
HAVE_ALLOCA_H = YesPlease
NO_STRLCPY = YesPlease
NO_MKSTEMPS = YesPlease
HAVE_PATHS_H = YesPlease
@ -313,6 +318,7 @@ endif
ifeq ($(uname_S),Windows)
GIT_VERSION := $(GIT_VERSION).MSVC
pathsep = ;
HAVE_ALLOCA_H = YesPlease
NO_PREAD = YesPlease
NEEDS_CRYPTO_WITH_SSL = YesPlease
NO_LIBGEN_H = YesPlease
@ -357,7 +363,7 @@ ifeq ($(uname_S),Windows)
COMPAT_OBJS = compat/msvc.o compat/winansi.o \
compat/win32/pthread.o compat/win32/syslog.o \
compat/win32/dirent.o
COMPAT_CFLAGS = -D__USE_MINGW_ACCESS -DNOGDI -DHAVE_STRING_H -DHAVE_ALLOCA_H -Icompat -Icompat/regex -Icompat/win32 -DSTRIP_EXTENSION=\".exe\"
COMPAT_CFLAGS = -D__USE_MINGW_ACCESS -DNOGDI -DHAVE_STRING_H -Icompat -Icompat/regex -Icompat/win32 -DSTRIP_EXTENSION=\".exe\"
BASIC_LDFLAGS = -IGNORE:4217 -IGNORE:4049 -NOLOGO -SUBSYSTEM:CONSOLE -NODEFAULTLIB:MSVCRT.lib
EXTLIBS = user32.lib advapi32.lib shell32.lib wininet.lib ws2_32.lib invalidcontinue.obj
PTHREAD_LIBS =
@ -465,6 +471,7 @@ ifeq ($(uname_S),NONSTOP_KERNEL)
endif
ifneq (,$(findstring MINGW,$(uname_S)))
pathsep = ;
HAVE_ALLOCA_H = YesPlease
NO_PREAD = YesPlease
NEEDS_CRYPTO_WITH_SSL = YesPlease
NO_LIBGEN_H = YesPlease

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@ -272,6 +272,14 @@ AS_HELP_STRING([], [ARG can be also prefix for libpcre library and hea
GIT_CONF_SUBST([LIBPCREDIR])
fi)
#
# Define HAVE_ALLOCA_H if you have working alloca(3) defined in that header.
AC_FUNC_ALLOCA
case $ac_cv_working_alloca_h in
yes) HAVE_ALLOCA_H=YesPlease;;
*) HAVE_ALLOCA_H='';;
esac
GIT_CONF_SUBST([HAVE_ALLOCA_H])
#
# Define NO_CURL if you do not have curl installed. git-http-pull and
# git-http-push are not built, and you cannot use http:// and https://
# transports.

2
diff.c
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@ -3205,6 +3205,7 @@ void diff_setup(struct diff_options *options)
options->context = diff_context_default;
DIFF_OPT_SET(options, RENAME_EMPTY);
/* pathchange left =NULL by default */
options->change = diff_change;
options->add_remove = diff_addremove;
options->use_color = diff_use_color_default;
@ -4749,6 +4750,7 @@ void diffcore_fix_diff_index(struct diff_options *options)
void diffcore_std(struct diff_options *options)
{
/* NOTE please keep the following in sync with diff_tree_combined() */
if (options->skip_stat_unmatch)
diffcore_skip_stat_unmatch(options);
if (!options->found_follow) {

11
diff.h
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@ -15,6 +15,10 @@ struct diff_filespec;
struct userdiff_driver;
struct sha1_array;
struct commit;
struct combine_diff_path;
typedef int (*pathchange_fn_t)(struct diff_options *options,
struct combine_diff_path *path);
typedef void (*change_fn_t)(struct diff_options *options,
unsigned old_mode, unsigned new_mode,
@ -157,6 +161,7 @@ struct diff_options {
int close_file;
struct pathspec pathspec;
pathchange_fn_t pathchange;
change_fn_t change;
add_remove_fn_t add_remove;
diff_format_fn_t format_callback;
@ -189,8 +194,10 @@ const char *diff_line_prefix(struct diff_options *);
extern const char mime_boundary_leader[];
extern int diff_tree(struct tree_desc *t1, struct tree_desc *t2,
const char *base, struct diff_options *opt);
extern struct combine_diff_path *diff_tree_paths(
struct combine_diff_path *p, const unsigned char *sha1,
const unsigned char **parent_sha1, int nparent,
struct strbuf *base, struct diff_options *opt);
extern int diff_tree_sha1(const unsigned char *old, const unsigned char *new,
const char *base, struct diff_options *opt);
extern int diff_root_tree_sha1(const unsigned char *new, const char *base,

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@ -521,6 +521,14 @@ extern void release_pack_memory(size_t);
typedef void (*try_to_free_t)(size_t);
extern try_to_free_t set_try_to_free_routine(try_to_free_t);
#ifdef HAVE_ALLOCA_H
# include <alloca.h>
# define xalloca(size) (alloca(size))
# define xalloca_free(p) do {} while (0)
#else
# define xalloca(size) (xmalloc(size))
# define xalloca_free(p) (free(p))
#endif
extern char *xstrdup(const char *str);
extern void *xmalloc(size_t size);
extern void *xmallocz(size_t size);

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@ -6,121 +6,293 @@
#include "diffcore.h"
#include "tree.h"
static void show_entry(struct diff_options *opt, const char *prefix,
struct tree_desc *desc, struct strbuf *base);
/*
* internal mode marker, saying a tree entry != entry of tp[imin]
* (see ll_diff_tree_paths for what it means there)
*
* we will update/use/emit entry for diff only with it unset.
*/
#define S_IFXMIN_NEQ S_DIFFTREE_IFXMIN_NEQ
static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2,
struct strbuf *base, struct diff_options *opt)
static struct combine_diff_path *ll_diff_tree_paths(
struct combine_diff_path *p, const unsigned char *sha1,
const unsigned char **parents_sha1, int nparent,
struct strbuf *base, struct diff_options *opt);
static int ll_diff_tree_sha1(const unsigned char *old, const unsigned char *new,
struct strbuf *base, struct diff_options *opt);
/*
* Compare two tree entries, taking into account only path/S_ISDIR(mode),
* but not their sha1's.
*
* NOTE files and directories *always* compare differently, even when having
* the same name - thanks to base_name_compare().
*
* NOTE empty (=invalid) descriptor(s) take part in comparison as +infty,
* so that they sort *after* valid tree entries.
*
* Due to this convention, if trees are scanned in sorted order, all
* non-empty descriptors will be processed first.
*/
static int tree_entry_pathcmp(struct tree_desc *t1, struct tree_desc *t2)
{
unsigned mode1, mode2;
const char *path1, *path2;
const unsigned char *sha1, *sha2;
int cmp, pathlen1, pathlen2;
int old_baselen = base->len;
struct name_entry *e1, *e2;
int cmp;
sha1 = tree_entry_extract(t1, &path1, &mode1);
sha2 = tree_entry_extract(t2, &path2, &mode2);
pathlen1 = tree_entry_len(&t1->entry);
pathlen2 = tree_entry_len(&t2->entry);
cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
if (cmp < 0) {
show_entry(opt, "-", t1, base);
/* empty descriptors sort after valid tree entries */
if (!t1->size)
return t2->size ? 1 : 0;
else if (!t2->size)
return -1;
}
if (cmp > 0) {
show_entry(opt, "+", t2, base);
return 1;
}
if (!DIFF_OPT_TST(opt, FIND_COPIES_HARDER) && !hashcmp(sha1, sha2) && mode1 == mode2)
return 0;
/*
* If the filemode has changed to/from a directory from/to a regular
* file, we need to consider it a remove and an add.
*/
if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
show_entry(opt, "-", t1, base);
show_entry(opt, "+", t2, base);
return 0;
}
strbuf_add(base, path1, pathlen1);
if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode1)) {
if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE)) {
opt->change(opt, mode1, mode2,
sha1, sha2, 1, 1, base->buf, 0, 0);
}
strbuf_addch(base, '/');
diff_tree_sha1(sha1, sha2, base->buf, opt);
} else {
opt->change(opt, mode1, mode2, sha1, sha2, 1, 1, base->buf, 0, 0);
}
strbuf_setlen(base, old_baselen);
return 0;
e1 = &t1->entry;
e2 = &t2->entry;
cmp = base_name_compare(e1->path, tree_entry_len(e1), e1->mode,
e2->path, tree_entry_len(e2), e2->mode);
return cmp;
}
/* A whole sub-tree went away or appeared */
static void show_tree(struct diff_options *opt, const char *prefix,
struct tree_desc *desc, struct strbuf *base)
/*
* convert path -> opt->diff_*() callbacks
*
* emits diff to first parent only, and tells diff tree-walker that we are done
* with p and it can be freed.
*/
static int emit_diff_first_parent_only(struct diff_options *opt, struct combine_diff_path *p)
{
enum interesting match = entry_not_interesting;
for (; desc->size; update_tree_entry(desc)) {
if (match != all_entries_interesting) {
match = tree_entry_interesting(&desc->entry, base, 0,
&opt->pathspec);
if (match == all_entries_not_interesting)
break;
if (match == entry_not_interesting)
continue;
}
show_entry(opt, prefix, desc, base);
struct combine_diff_parent *p0 = &p->parent[0];
if (p->mode && p0->mode) {
opt->change(opt, p0->mode, p->mode, p0->sha1, p->sha1,
1, 1, p->path, 0, 0);
}
else {
const unsigned char *sha1;
unsigned int mode;
int addremove;
if (p->mode) {
addremove = '+';
sha1 = p->sha1;
mode = p->mode;
} else {
addremove = '-';
sha1 = p0->sha1;
mode = p0->mode;
}
opt->add_remove(opt, addremove, mode, sha1, 1, p->path, 0);
}
return 0; /* we are done with p */
}
/* A file entry went away or appeared */
static void show_entry(struct diff_options *opt, const char *prefix,
struct tree_desc *desc, struct strbuf *base)
/*
* Make a new combine_diff_path from path/mode/sha1
* and append it to paths list tail.
*
* Memory for created elements could be reused:
*
* - if last->next == NULL, the memory is allocated;
*
* - if last->next != NULL, it is assumed that p=last->next was returned
* earlier by this function, and p->next was *not* modified.
* The memory is then reused from p.
*
* so for clients,
*
* - if you do need to keep the element
*
* p = path_appendnew(p, ...);
* process(p);
* p->next = NULL;
*
* - if you don't need to keep the element after processing
*
* pprev = p;
* p = path_appendnew(p, ...);
* process(p);
* p = pprev;
* ; don't forget to free tail->next in the end
*
* p->parent[] remains uninitialized.
*/
static struct combine_diff_path *path_appendnew(struct combine_diff_path *last,
int nparent, const struct strbuf *base, const char *path, int pathlen,
unsigned mode, const unsigned char *sha1)
{
struct combine_diff_path *p;
int len = base->len + pathlen;
int alloclen = combine_diff_path_size(nparent, len);
/* if last->next is !NULL - it is a pre-allocated memory, we can reuse */
p = last->next;
if (p && (alloclen > (intptr_t)p->next)) {
free(p);
p = NULL;
}
if (!p) {
p = xmalloc(alloclen);
/*
* until we go to it next round, .next holds how many bytes we
* allocated (for faster realloc - we don't need copying old data).
*/
p->next = (struct combine_diff_path *)(intptr_t)alloclen;
}
last->next = p;
p->path = (char *)&(p->parent[nparent]);
memcpy(p->path, base->buf, base->len);
memcpy(p->path + base->len, path, pathlen);
p->path[len] = 0;
p->mode = mode;
hashcpy(p->sha1, sha1 ? sha1 : null_sha1);
return p;
}
/*
* new path should be added to combine diff
*
* 3 cases on how/when it should be called and behaves:
*
* t, !tp -> path added, all parents lack it
* !t, tp -> path removed from all parents
* t, tp -> path modified/added
* (M for tp[i]=tp[imin], A otherwise)
*/
static struct combine_diff_path *emit_path(struct combine_diff_path *p,
struct strbuf *base, struct diff_options *opt, int nparent,
struct tree_desc *t, struct tree_desc *tp,
int imin)
{
unsigned mode;
const char *path;
const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);
int pathlen = tree_entry_len(&desc->entry);
const unsigned char *sha1;
int pathlen;
int old_baselen = base->len;
int i, isdir, recurse = 0, emitthis = 1;
strbuf_add(base, path, pathlen);
if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode)) {
enum object_type type;
struct tree_desc inner;
void *tree;
unsigned long size;
/* at least something has to be valid */
assert(t || tp);
tree = read_sha1_file(sha1, &type, &size);
if (!tree || type != OBJ_TREE)
die("corrupt tree sha %s", sha1_to_hex(sha1));
if (t) {
/* path present in resulting tree */
sha1 = tree_entry_extract(t, &path, &mode);
pathlen = tree_entry_len(&t->entry);
isdir = S_ISDIR(mode);
} else {
/*
* a path was removed - take path from imin parent. Also take
* mode from that parent, to decide on recursion(1).
*
* 1) all modes for tp[i]=tp[imin] should be the same wrt
* S_ISDIR, thanks to base_name_compare().
*/
tree_entry_extract(&tp[imin], &path, &mode);
pathlen = tree_entry_len(&tp[imin].entry);
if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE))
opt->add_remove(opt, *prefix, mode, sha1, 1, base->buf, 0);
isdir = S_ISDIR(mode);
sha1 = NULL;
mode = 0;
}
if (DIFF_OPT_TST(opt, RECURSIVE) && isdir) {
recurse = 1;
emitthis = DIFF_OPT_TST(opt, TREE_IN_RECURSIVE);
}
if (emitthis) {
int keep;
struct combine_diff_path *pprev = p;
p = path_appendnew(p, nparent, base, path, pathlen, mode, sha1);
for (i = 0; i < nparent; ++i) {
/*
* tp[i] is valid, if present and if tp[i]==tp[imin] -
* otherwise, we should ignore it.
*/
int tpi_valid = tp && !(tp[i].entry.mode & S_IFXMIN_NEQ);
const unsigned char *sha1_i;
unsigned mode_i;
p->parent[i].status =
!t ? DIFF_STATUS_DELETED :
tpi_valid ?
DIFF_STATUS_MODIFIED :
DIFF_STATUS_ADDED;
if (tpi_valid) {
sha1_i = tp[i].entry.sha1;
mode_i = tp[i].entry.mode;
}
else {
sha1_i = NULL;
mode_i = 0;
}
p->parent[i].mode = mode_i;
hashcpy(p->parent[i].sha1, sha1_i ? sha1_i : null_sha1);
}
keep = 1;
if (opt->pathchange)
keep = opt->pathchange(opt, p);
/*
* If a path was filtered or consumed - we don't need to add it
* to the list and can reuse its memory, leaving it as
* pre-allocated element on the tail.
*
* On the other hand, if path needs to be kept, we need to
* correct its .next to NULL, as it was pre-initialized to how
* much memory was allocated.
*
* see path_appendnew() for details.
*/
if (!keep)
p = pprev;
else
p->next = NULL;
}
if (recurse) {
const unsigned char **parents_sha1;
parents_sha1 = xalloca(nparent * sizeof(parents_sha1[0]));
for (i = 0; i < nparent; ++i) {
/* same rule as in emitthis */
int tpi_valid = tp && !(tp[i].entry.mode & S_IFXMIN_NEQ);
parents_sha1[i] = tpi_valid ? tp[i].entry.sha1
: NULL;
}
strbuf_add(base, path, pathlen);
strbuf_addch(base, '/');
init_tree_desc(&inner, tree, size);
show_tree(opt, prefix, &inner, base);
free(tree);
} else
opt->add_remove(opt, prefix[0], mode, sha1, 1, base->buf, 0);
p = ll_diff_tree_paths(p, sha1, parents_sha1, nparent, base, opt);
xalloca_free(parents_sha1);
}
strbuf_setlen(base, old_baselen);
return p;
}
static void skip_uninteresting(struct tree_desc *t, struct strbuf *base,
struct diff_options *opt,
enum interesting *match)
struct diff_options *opt)
{
enum interesting match;
while (t->size) {
*match = tree_entry_interesting(&t->entry, base, 0, &opt->pathspec);
if (*match) {
if (*match == all_entries_not_interesting)
match = tree_entry_interesting(&t->entry, base, 0, &opt->pathspec);
if (match) {
if (match == all_entries_not_interesting)
t->size = 0;
break;
}
@ -128,55 +300,260 @@ static void skip_uninteresting(struct tree_desc *t, struct strbuf *base,
}
}
int diff_tree(struct tree_desc *t1, struct tree_desc *t2,
const char *base_str, struct diff_options *opt)
/*
* generate paths for combined diff D(sha1,parents_sha1[])
*
* Resulting paths are appended to combine_diff_path linked list, and also, are
* emitted on the go via opt->pathchange() callback, so it is possible to
* process the result as batch or incrementally.
*
* The paths are generated scanning new tree and all parents trees
* simultaneously, similarly to what diff_tree() was doing for 2 trees.
* The theory behind such scan is as follows:
*
*
* D(T,P1...Pn) calculation scheme
* -------------------------------
*
* D(T,P1...Pn) = D(T,P1) ^ ... ^ D(T,Pn) (regarding resulting paths set)
*
* D(T,Pj) - diff between T..Pj
* D(T,P1...Pn) - combined diff from T to parents P1,...,Pn
*
*
* We start from all trees, which are sorted, and compare their entries in
* lock-step:
*
* T P1 Pn
* - - -
* |t| |p1| |pn|
* |-| |--| ... |--| imin = argmin(p1...pn)
* | | | | | |
* |-| |--| |--|
* |.| |. | |. |
* . . .
* . . .
*
* at any time there could be 3 cases:
*
* 1) t < p[imin];
* 2) t > p[imin];
* 3) t = p[imin].
*
* Schematic deduction of what every case means, and what to do, follows:
*
* 1) t < p[imin] -> j t Pj -> "+t" D(T,Pj) -> D += "+t"; t
*
* 2) t > p[imin]
*
* 2.1) j: pj > p[imin] -> "-p[imin]" D(T,Pj) -> D += ø; pi=p[imin] pi
* 2.2) i pi = p[imin] -> pi T -> "-pi" D(T,Pi) -> D += "-p[imin]"; i pi
*
* 3) t = p[imin]
*
* 3.1) j: pj > p[imin] -> "+t" D(T,Pj) -> only pi=p[imin] remains to investigate
* 3.2) pi = p[imin] -> investigate δ(t,pi)
* |
* |
* v
*
* 3.1+3.2) looking at δ(t,pi) i: pi=p[imin] - if all != ø ->
*
* δ(t,pi) - if pi=p[imin]
* -> D +=
* "+t" - if pi>p[imin]
*
*
* in any case t pi=p[imin] pi
*
*
* ~~~~~~~~
*
* NOTE
*
* Usual diff D(A,B) is by definition the same as combined diff D(A,[B]),
* so this diff paths generator can, and is used, for plain diffs
* generation too.
*
* Please keep attention to the common D(A,[B]) case when working on the
* code, in order not to slow it down.
*
* NOTE
* nparent must be > 0.
*/
/* ∀ pi=p[imin] pi↓ */
static inline void update_tp_entries(struct tree_desc *tp, int nparent)
{
struct strbuf base;
int baselen = strlen(base_str);
enum interesting t1_match = entry_not_interesting;
enum interesting t2_match = entry_not_interesting;
int i;
for (i = 0; i < nparent; ++i)
if (!(tp[i].entry.mode & S_IFXMIN_NEQ))
update_tree_entry(&tp[i]);
}
static struct combine_diff_path *ll_diff_tree_paths(
struct combine_diff_path *p, const unsigned char *sha1,
const unsigned char **parents_sha1, int nparent,
struct strbuf *base, struct diff_options *opt)
{
struct tree_desc t, *tp;
void *ttree, **tptree;
int i;
tp = xalloca(nparent * sizeof(tp[0]));
tptree = xalloca(nparent * sizeof(tptree[0]));
/*
* load parents first, as they are probably already cached.
*
* ( log_tree_diff() parses commit->parent before calling here via
* diff_tree_sha1(parent, commit) )
*/
for (i = 0; i < nparent; ++i)
tptree[i] = fill_tree_descriptor(&tp[i], parents_sha1[i]);
ttree = fill_tree_descriptor(&t, sha1);
/* Enable recursion indefinitely */
opt->pathspec.recursive = DIFF_OPT_TST(opt, RECURSIVE);
strbuf_init(&base, PATH_MAX);
strbuf_add(&base, base_str, baselen);
for (;;) {
int imin, cmp;
if (diff_can_quit_early(opt))
break;
if (opt->pathspec.nr) {
skip_uninteresting(t1, &base, opt, &t1_match);
skip_uninteresting(t2, &base, opt, &t2_match);
skip_uninteresting(&t, base, opt);
for (i = 0; i < nparent; i++)
skip_uninteresting(&tp[i], base, opt);
}
if (!t1->size) {
if (!t2->size)
/* comparing is finished when all trees are done */
if (!t.size) {
int done = 1;
for (i = 0; i < nparent; ++i)
if (tp[i].size) {
done = 0;
break;
}
if (done)
break;
show_entry(opt, "+", t2, &base);
update_tree_entry(t2);
continue;
}
if (!t2->size) {
show_entry(opt, "-", t1, &base);
update_tree_entry(t1);
continue;
/*
* lookup imin = argmin(p1...pn),
* mark entries whether they =p[imin] along the way
*/
imin = 0;
tp[0].entry.mode &= ~S_IFXMIN_NEQ;
for (i = 1; i < nparent; ++i) {
cmp = tree_entry_pathcmp(&tp[i], &tp[imin]);
if (cmp < 0) {
imin = i;
tp[i].entry.mode &= ~S_IFXMIN_NEQ;
}
else if (cmp == 0) {
tp[i].entry.mode &= ~S_IFXMIN_NEQ;
}
else {
tp[i].entry.mode |= S_IFXMIN_NEQ;
}
}
switch (compare_tree_entry(t1, t2, &base, opt)) {
case -1:
update_tree_entry(t1);
continue;
case 0:
update_tree_entry(t1);
/* Fallthrough */
case 1:
update_tree_entry(t2);
continue;
/* fixup markings for entries before imin */
for (i = 0; i < imin; ++i)
tp[i].entry.mode |= S_IFXMIN_NEQ; /* pi > p[imin] */
/* compare t vs p[imin] */
cmp = tree_entry_pathcmp(&t, &tp[imin]);
/* t = p[imin] */
if (cmp == 0) {
/* are either pi > p[imin] or diff(t,pi) != ø ? */
if (!DIFF_OPT_TST(opt, FIND_COPIES_HARDER)) {
for (i = 0; i < nparent; ++i) {
/* p[i] > p[imin] */
if (tp[i].entry.mode & S_IFXMIN_NEQ)
continue;
/* diff(t,pi) != ø */
if (hashcmp(t.entry.sha1, tp[i].entry.sha1) ||
(t.entry.mode != tp[i].entry.mode))
continue;
goto skip_emit_t_tp;
}
}
/* D += {δ(t,pi) if pi=p[imin]; "+a" if pi > p[imin]} */
p = emit_path(p, base, opt, nparent,
&t, tp, imin);
skip_emit_t_tp:
/* t↓, ∀ pi=p[imin] pi↓ */
update_tree_entry(&t);
update_tp_entries(tp, nparent);
}
/* t < p[imin] */
else if (cmp < 0) {
/* D += "+t" */
p = emit_path(p, base, opt, nparent,
&t, /*tp=*/NULL, -1);
/* t↓ */
update_tree_entry(&t);
}
/* t > p[imin] */
else {
/* ∀i pi=p[imin] -> D += "-p[imin]" */
if (!DIFF_OPT_TST(opt, FIND_COPIES_HARDER)) {
for (i = 0; i < nparent; ++i)
if (tp[i].entry.mode & S_IFXMIN_NEQ)
goto skip_emit_tp;
}
p = emit_path(p, base, opt, nparent,
/*t=*/NULL, tp, imin);
skip_emit_tp:
/* ∀ pi=p[imin] pi↓ */
update_tp_entries(tp, nparent);
}
die("git diff-tree: internal error");
}
strbuf_release(&base);
return 0;
free(ttree);
for (i = nparent-1; i >= 0; i--)
free(tptree[i]);
xalloca_free(tptree);
xalloca_free(tp);
return p;
}
struct combine_diff_path *diff_tree_paths(
struct combine_diff_path *p, const unsigned char *sha1,
const unsigned char **parents_sha1, int nparent,
struct strbuf *base, struct diff_options *opt)
{
p = ll_diff_tree_paths(p, sha1, parents_sha1, nparent, base, opt);
/*
* free pre-allocated last element, if any
* (see path_appendnew() for details about why)
*/
if (p->next) {
free(p->next);
p->next = NULL;
}
return p;
}
/*
@ -190,7 +567,7 @@ static inline int diff_might_be_rename(void)
!DIFF_FILE_VALID(diff_queued_diff.queue[0]->one);
}
static void try_to_follow_renames(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
static void try_to_follow_renames(const unsigned char *old, const unsigned char *new, struct strbuf *base, struct diff_options *opt)
{
struct diff_options diff_opts;
struct diff_queue_struct *q = &diff_queued_diff;
@ -228,7 +605,7 @@ static void try_to_follow_renames(struct tree_desc *t1, struct tree_desc *t2, co
diff_opts.break_opt = opt->break_opt;
diff_opts.rename_score = opt->rename_score;
diff_setup_done(&diff_opts);
diff_tree(t1, t2, base, &diff_opts);
ll_diff_tree_sha1(old, new, base, &diff_opts);
diffcore_std(&diff_opts);
free_pathspec(&diff_opts.pathspec);
@ -287,25 +664,40 @@ static void try_to_follow_renames(struct tree_desc *t1, struct tree_desc *t2, co
q->nr = 1;
}
int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base, struct diff_options *opt)
static int ll_diff_tree_sha1(const unsigned char *old, const unsigned char *new,
struct strbuf *base, struct diff_options *opt)
{
void *tree1, *tree2;
struct tree_desc t1, t2;
unsigned long size1, size2;
struct combine_diff_path phead, *p;
pathchange_fn_t pathchange_old = opt->pathchange;
phead.next = NULL;
opt->pathchange = emit_diff_first_parent_only;
diff_tree_paths(&phead, new, &old, 1, base, opt);
for (p = phead.next; p;) {
struct combine_diff_path *pprev = p;
p = p->next;
free(pprev);
}
opt->pathchange = pathchange_old;
return 0;
}
int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base_str, struct diff_options *opt)
{
struct strbuf base;
int retval;
tree1 = fill_tree_descriptor(&t1, old);
tree2 = fill_tree_descriptor(&t2, new);
size1 = t1.size;
size2 = t2.size;
retval = diff_tree(&t1, &t2, base, opt);
if (!*base && DIFF_OPT_TST(opt, FOLLOW_RENAMES) && diff_might_be_rename()) {
init_tree_desc(&t1, tree1, size1);
init_tree_desc(&t2, tree2, size2);
try_to_follow_renames(&t1, &t2, base, opt);
}
free(tree1);
free(tree2);
strbuf_init(&base, PATH_MAX);
strbuf_addstr(&base, base_str);
retval = ll_diff_tree_sha1(old, new, &base, opt);
if (!*base_str && DIFF_OPT_TST(opt, FOLLOW_RENAMES) && diff_might_be_rename())
try_to_follow_renames(old, new, &base, opt);
strbuf_release(&base);
return retval;
}