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-rw-r--r--Makefile6
-rw-r--r--cache.h15
-rw-r--r--combine-diff.c168
-rw-r--r--compat/win32/alloca.h (renamed from compat/vcbuild/include/alloca.h)0
-rw-r--r--config.mak.uname11
-rw-r--r--configure.ac8
-rw-r--r--diff.c2
-rw-r--r--diff.h11
-rw-r--r--git-compat-util.h8
-rw-r--r--tree-diff.c664
10 files changed, 723 insertions, 170 deletions
diff --git a/Makefile b/Makefile
index a53f3a8..1f5d924 100644
--- a/Makefile
+++ b/Makefile
@@ -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 =
diff --git a/cache.h b/cache.h
index 107ac61..ef4412d 100644
--- a/cache.h
+++ b/cache.h
@@ -75,6 +75,21 @@ unsigned long git_deflate_bound(git_zstream *, unsigned long);
#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
*
diff --git a/combine-diff.c b/combine-diff.c
index 24ca7e2..12764fb 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -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;
+
+ /* nothing to do, if no parents */
+ if (!num_parent)
+ return;
+
+ show_log_first = !!rev->loginfo && !rev->no_commit_id;
+ needsep = 0;
+ 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);
- 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;
- 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
+ /* 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 */
diff --git a/compat/vcbuild/include/alloca.h b/compat/win32/alloca.h
index c0d7985..c0d7985 100644
--- a/compat/vcbuild/include/alloca.h
+++ b/compat/win32/alloca.h
diff --git a/config.mak.uname b/config.mak.uname
index 23a8803..97acf8f 100644
--- a/config.mak.uname
+++ b/config.mak.uname
@@ -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
diff --git a/configure.ac b/configure.ac
index b711254..4b1ae7c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -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.
diff --git a/diff.c b/diff.c
index f72769a..36679aa 100644
--- a/diff.c
+++ b/diff.c
@@ -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) {
diff --git a/diff.h b/diff.h
index a24a767..b4a624d 100644
--- a/diff.h
+++ b/diff.h
@@ -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,
diff --git a/git-compat-util.h b/git-compat-util.h
index f6d3a46..7fe1ffda0 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -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);
diff --git a/tree-diff.c b/tree-diff.c
index 11c3550..e7b378c 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -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)
-{
- unsigned mode1, mode2;
- const char *path1, *path2;
- const unsigned char *sha1, *sha2;
- int cmp, pathlen1, pathlen2;
- int old_baselen = base->len;
- sha1 = tree_entry_extract(t1, &path1, &mode1);
- sha2 = tree_entry_extract(t2, &path2, &mode2);
+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)
+{
+ struct name_entry *e1, *e2;
+ int cmp;
- 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;
- }
+ 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;
+}
- 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);
+
+/*
+ * 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)
+{
+ 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;
}
- 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);
+
+ opt->add_remove(opt, addremove, mode, sha1, 1, p->path, 0);
}
- strbuf_setlen(base, old_baselen);
- return 0;
+
+ return 0; /* we are done with p */
}
-/* 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)
+
+/*
+ * 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)
{
- 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_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;
}
-/* 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)
+/*
+ * 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;
+
+ /* at least something has to be valid */
+ assert(t || tp);
- 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;
+ 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);
- tree = read_sha1_file(sha1, &type, &size);
- if (!tree || type != OBJ_TREE)
- die("corrupt tree sha %s", sha1_to_hex(sha1));
+ isdir = S_ISDIR(mode);
+ sha1 = NULL;
+ mode = 0;
+ }
- if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE))
- opt->add_remove(opt, *prefix, mode, sha1, 1, base->buf, 0);
+ if (DIFF_OPT_TST(opt, RECURSIVE) && isdir) {
+ recurse = 1;
+ emitthis = DIFF_OPT_TST(opt, TREE_IN_RECURSIVE);
+ }
- strbuf_addch(base, '/');
+ if (emitthis) {
+ int keep;
+ struct combine_diff_path *pprev = p;
+ p = path_appendnew(p, nparent, base, path, pathlen, mode, sha1);
- 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);
+ 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, '/');
+ 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;
+ }
+ }
+
+ /* 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);
}
- 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;
+
+ /* 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;
- int retval;
+ struct combine_diff_path phead, *p;
+ pathchange_fn_t pathchange_old = opt->pathchange;
- 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);
+ 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);
}
- free(tree1);
- free(tree2);
+
+ 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;
+
+ 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;
}