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Re: [PATCH 3/3] pretty=format: Avoid some expensive calculations when not needed

From
René Scharfe <rene.scharfe@lsrfire.ath.cx>
Date
Nov 6, 2007, 23:17 UTC
Message-ID
<4730F5FA.3030705@lsrfire.ath.cx>
In-Reply-To
<4730EB4E.4080903@lsrfire.ath.cx>

By the way, the more intrusive surgery required when using strbuf_expand() leads to even faster operation. Here my measurements of most of Paul's test cases (best of three runs):

# master $ time git log --pretty=oneline >/dev/null

real 0m0.390s user 0m0.340s sys 0m0.040s

# master $ time git log --pretty=raw >/dev/null

real 0m0.434s user 0m0.408s sys 0m0.016s

# master $ time git log --pretty="format:%H {%P} %ct" >/dev/null

real 0m1.347s user 0m0.080s sys 0m1.256s

# interp_find_active $ time ./git log --pretty="format:%H {%P} %ct" >/dev/null

real 0m0.694s user 0m0.020s sys 0m0.672s

# strbuf_expand $ time ./git log --pretty="format:%H {%P} %ct" >/dev/null

real 0m0.395s user 0m0.352s sys 0m0.028s

I haven't seen any comments on strbuf_expand. Is it too far out? Here it is again, adjusted for current master and with the changes to strbuf.[ch] coming first:

 strbuf.c |   22 +++++
 strbuf.h |    3 
 pretty.c |  276 ++++++++++++++++++++++++++++++++++-----------------------------
 3 files changed, 178 insertions(+), 123 deletions(-)
diff --git a/strbuf.c b/strbuf.c
index f4201e1..b71da99 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -129,6 +129,28 @@ void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
 	strbuf_setlen(sb, sb->len + len);
 }
 
+void strbuf_expand(struct strbuf *sb, const char *fmt,
+                   const char **placeholders, expand_fn_t fn, void *context)
+{
+	char c;
+	const char **p;
+
+	while ((c = *fmt++)) {
+		if (c != '%') {
+			strbuf_addch(sb, c);
+			continue;
+		}
+
+		for (p = placeholders; *p; p++) {
+			if (!prefixcmp(fmt, *p)) {
+				fn(sb, *p, context);
+				fmt += strlen(*p);
+				break;
+			}
+		}
+	}
+}
+
 size_t strbuf_fread(struct strbuf *sb, size_t size, FILE *f)
 {
 	size_t res;
diff --git a/strbuf.h b/strbuf.h
index cd7f295..95071d5 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -102,6 +102,9 @@ static inline void strbuf_addbuf(struct strbuf *sb, struct strbuf *sb2) {
 	strbuf_add(sb, sb2->buf, sb2->len);
 }
 
+typedef void (*expand_fn_t) (struct strbuf *sb, const char *placeholder, void *context);
+extern void strbuf_expand(struct strbuf *sb, const char *fmt, const char **placeholders, expand_fn_t fn, void *context);
+
 __attribute__((format(printf,2,3)))
 extern void strbuf_addf(struct strbuf *sb, const char *fmt, ...);
 
diff --git a/pretty.c b/pretty.c
index 490cede..ea644bb 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1,6 +1,5 @@
 #include "cache.h"
 #include "commit.h"
-#include "interpolate.h"
 #include "utf8.h"
 #include "diff.h"
 #include "revision.h"
@@ -283,7 +282,8 @@ static char *logmsg_reencode(const struct commit *commit,
 	return out;
 }
 
-static void fill_person(struct interp *table, const char *msg, int len)
+static void format_person_part(struct strbuf *sb, char part,
+                               const char *msg, int len)
 {
 	int start, end, tz = 0;
 	unsigned long date;
@@ -295,7 +295,10 @@ static void fill_person(struct interp *table, const char *msg, int len)
 	start = end + 1;
 	while (end > 0 && isspace(msg[end - 1]))
 		end--;
-	table[0].value = xmemdupz(msg, end);
+	if (part == 'n') {	/* name */
+		strbuf_add(sb, msg, end);
+		return;
+	}
 
 	if (start >= len)
 		return;
@@ -307,7 +310,10 @@ static void fill_person(struct interp *table, const char *msg, int len)
 	if (end >= len)
 		return;
 
-	table[1].value = xmemdupz(msg + start, end - start);
+	if (part == 'e') {	/* email */
+		strbuf_add(sb, msg + start, end - start);
+		return;
+	}
 
 	/* parse date */
 	for (start = end + 1; start < len && isspace(msg[start]); start++)
@@ -318,7 +324,10 @@ static void fill_person(struct interp *table, const char *msg, int len)
 	if (msg + start == ep)
 		return;
 
-	table[5].value = xmemdupz(msg + start, ep - (msg + start));
+	if (part == 't') {	/* date, UNIX timestamp */
+		strbuf_add(sb, msg + start, ep - (msg + start));
+		return;
+	}
 
 	/* parse tz */
 	for (start = ep - msg + 1; start < len && isspace(msg[start]); start++)
@@ -329,123 +338,107 @@ static void fill_person(struct interp *table, const char *msg, int len)
 			tz = -tz;
 	}
 
-	interp_set_entry(table, 2, show_date(date, tz, DATE_NORMAL));
-	interp_set_entry(table, 3, show_date(date, tz, DATE_RFC2822));
-	interp_set_entry(table, 4, show_date(date, tz, DATE_RELATIVE));
-	interp_set_entry(table, 6, show_date(date, tz, DATE_ISO8601));
+	switch (part) {
+	case 'd':	/* date */
+		strbuf_addstr(sb, show_date(date, tz, DATE_NORMAL));
+		return;
+	case 'D':	/* date, RFC2822 style */
+		strbuf_addstr(sb, show_date(date, tz, DATE_RFC2822));
+		return;
+	case 'r':	/* date, relative */
+		strbuf_addstr(sb, show_date(date, tz, DATE_RELATIVE));
+		return;
+	case 'i':	/* date, ISO 8601 */
+		strbuf_addstr(sb, show_date(date, tz, DATE_ISO8601));
+		return;
+	}
 }
 
-void format_commit_message(const struct commit *commit,
-                           const void *format, struct strbuf *sb)
+static void format_commit_item(struct strbuf *sb, const char *placeholder,
+                               void *context)
 {
-	struct interp table[] = {
-		{ "%H" },	/* commit hash */
-		{ "%h" },	/* abbreviated commit hash */
-		{ "%T" },	/* tree hash */
-		{ "%t" },	/* abbreviated tree hash */
-		{ "%P" },	/* parent hashes */
-		{ "%p" },	/* abbreviated parent hashes */
-		{ "%an" },	/* author name */
-		{ "%ae" },	/* author email */
-		{ "%ad" },	/* author date */
-		{ "%aD" },	/* author date, RFC2822 style */
-		{ "%ar" },	/* author date, relative */
-		{ "%at" },	/* author date, UNIX timestamp */
-		{ "%ai" },	/* author date, ISO 8601 */
-		{ "%cn" },	/* committer name */
-		{ "%ce" },	/* committer email */
-		{ "%cd" },	/* committer date */
-		{ "%cD" },	/* committer date, RFC2822 style */
-		{ "%cr" },	/* committer date, relative */
-		{ "%ct" },	/* committer date, UNIX timestamp */
-		{ "%ci" },	/* committer date, ISO 8601 */
-		{ "%e" },	/* encoding */
-		{ "%s" },	/* subject */
-		{ "%b" },	/* body */
-		{ "%Cred" },	/* red */
-		{ "%Cgreen" },	/* green */
-		{ "%Cblue" },	/* blue */
-		{ "%Creset" },	/* reset color */
-		{ "%n" },	/* newline */
-		{ "%m" },	/* left/right/bottom */
-	};
-	enum interp_index {
-		IHASH = 0, IHASH_ABBREV,
-		ITREE, ITREE_ABBREV,
-		IPARENTS, IPARENTS_ABBREV,
-		IAUTHOR_NAME, IAUTHOR_EMAIL,
-		IAUTHOR_DATE, IAUTHOR_DATE_RFC2822, IAUTHOR_DATE_RELATIVE,
-		IAUTHOR_TIMESTAMP, IAUTHOR_ISO8601,
-		ICOMMITTER_NAME, ICOMMITTER_EMAIL,
-		ICOMMITTER_DATE, ICOMMITTER_DATE_RFC2822,
-		ICOMMITTER_DATE_RELATIVE, ICOMMITTER_TIMESTAMP,
-		ICOMMITTER_ISO8601,
-		IENCODING,
-		ISUBJECT,
-		IBODY,
-		IRED, IGREEN, IBLUE, IRESET_COLOR,
-		INEWLINE,
-		ILEFT_RIGHT,
-	};
+	const struct commit *commit = context;
 	struct commit_list *p;
-	char parents[1024];
-	unsigned long len;
 	int i;
 	enum { HEADER, SUBJECT, BODY } state;
 	const char *msg = commit->buffer;
 
-	if (ILEFT_RIGHT + 1 != ARRAY_SIZE(table))
-		die("invalid interp table!");
-
 	/* these are independent of the commit */
-	interp_set_entry(table, IRED, "\033[31m");
-	interp_set_entry(table, IGREEN, "\033[32m");
-	interp_set_entry(table, IBLUE, "\033[34m");
-	interp_set_entry(table, IRESET_COLOR, "\033[m");
-	interp_set_entry(table, INEWLINE, "\n");
+	switch (placeholder[0]) {
+	case 'C':
+		switch (placeholder[3]) {
+		case 'd':	/* red */
+			strbuf_addstr(sb, "\033[31m");
+			return;
+		case 'e':	/* green */
+			strbuf_addstr(sb, "\033[32m");
+			return;
+		case 'u':	/* blue */
+			strbuf_addstr(sb, "\033[34m");
+			return;
+		case 's':	/* reset color */
+			strbuf_addstr(sb, "\033[m");
+			return;
+		}
+	case 'n':		/* newline */
+		strbuf_addch(sb, '\n');
+		return;
+	}
 
 	/* these depend on the commit */
 	if (!commit->object.parsed)
 		parse_object(commit->object.sha1);
-	interp_set_entry(table, IHASH, sha1_to_hex(commit->object.sha1));
-	interp_set_entry(table, IHASH_ABBREV,
-			find_unique_abbrev(commit->object.sha1,
-				DEFAULT_ABBREV));
-	interp_set_entry(table, ITREE, sha1_to_hex(commit->tree->object.sha1));
-	interp_set_entry(table, ITREE_ABBREV,
-			find_unique_abbrev(commit->tree->object.sha1,
-				DEFAULT_ABBREV));
-	interp_set_entry(table, ILEFT_RIGHT,
-			 (commit->object.flags & BOUNDARY)
-			 ? "-"
-			 : (commit->object.flags & SYMMETRIC_LEFT)
-			 ? "<"
-			 : ">");
-
-	parents[1] = 0;
-	for (i = 0, p = commit->parents;
-			p && i < sizeof(parents) - 1;
-			p = p->next)
-		i += snprintf(parents + i, sizeof(parents) - i - 1, " %s",
-			sha1_to_hex(p->item->object.sha1));
-	interp_set_entry(table, IPARENTS, parents + 1);
-
-	parents[1] = 0;
-	for (i = 0, p = commit->parents;
-			p && i < sizeof(parents) - 1;
-			p = p->next)
-		i += snprintf(parents + i, sizeof(parents) - i - 1, " %s",
-			find_unique_abbrev(p->item->object.sha1,
-				DEFAULT_ABBREV));
-	interp_set_entry(table, IPARENTS_ABBREV, parents + 1);
 
+	switch (placeholder[0]) {
+	case 'H':		/* commit hash */
+		strbuf_addstr(sb, sha1_to_hex(commit->object.sha1));
+		return;
+	case 'h':		/* abbreviated commit hash */
+		strbuf_addstr(sb, find_unique_abbrev(commit->object.sha1,
+		                                     DEFAULT_ABBREV));
+		return;
+	case 'T':		/* tree hash */
+		strbuf_addstr(sb, sha1_to_hex(commit->tree->object.sha1));
+		return;
+	case 't':		/* abbreviated tree hash */
+		strbuf_addstr(sb, find_unique_abbrev(commit->tree->object.sha1,
+		                                     DEFAULT_ABBREV));
+		return;
+	case 'P':		/* parent hashes */
+		for (p = commit->parents; p; p = p->next) {
+			if (p != commit->parents)
+				strbuf_addch(sb, ' ');
+			strbuf_addstr(sb, sha1_to_hex(p->item->object.sha1));
+		}
+		return;
+	case 'p':		/* abbreviated parent hashes */
+		for (p = commit->parents; p; p = p->next) {
+			if (p != commit->parents)
+				strbuf_addch(sb, ' ');
+			strbuf_addstr(sb, find_unique_abbrev(
+					p->item->object.sha1, DEFAULT_ABBREV));
+		}
+		return;
+	case 'm':		/* left/right/bottom */
+		strbuf_addch(sb, (commit->object.flags & BOUNDARY)
+		                 ? '-'
+		                 : (commit->object.flags & SYMMETRIC_LEFT)
+		                 ? '<'
+		                 : '>');
+		return;
+	}
+
+	/* For the rest we have to parse the commit header. */
 	for (i = 0, state = HEADER; msg[i] && state < BODY; i++) {
 		int eol;
 		for (eol = i; msg[eol] && msg[eol] != '\n'; eol++)
 			; /* do nothing */
 
 		if (state == SUBJECT) {
-			table[ISUBJECT].value = xmemdupz(msg + i, eol - i);
+			if (placeholder[0] == 's') {
+				strbuf_add(sb, msg + i, eol - i);
+				return;
+			}
 			i = eol;
 		}
 		if (i == eol) {
@@ -453,29 +446,66 @@ void format_commit_message(const struct commit *commit,
 			/* strip empty lines */
 			while (msg[eol + 1] == '\n')
 				eol++;
-		} else if (!prefixcmp(msg + i, "author "))
-			fill_person(table + IAUTHOR_NAME,
-					msg + i + 7, eol - i - 7);
-		else if (!prefixcmp(msg + i, "committer "))
-			fill_person(table + ICOMMITTER_NAME,
-					msg + i + 10, eol - i - 10);
-		else if (!prefixcmp(msg + i, "encoding "))
-			table[IENCODING].value =
-				xmemdupz(msg + i + 9, eol - i - 9);
+		} else if (!prefixcmp(msg + i, "author ")) {
+			if (placeholder[0] == 'a') {
+				format_person_part(sb, placeholder[1],
+				                   msg + i + 7, eol - i - 7);
+				return;
+			}
+		} else if (!prefixcmp(msg + i, "committer ")) {
+			if (placeholder[0] == 'c') {
+				format_person_part(sb, placeholder[1],
+				                   msg + i + 10, eol - i - 10);
+				return;
+			}
+		} else if (!prefixcmp(msg + i, "encoding ")) {
+			if (placeholder[0] == 'e') {
+				strbuf_add(sb, msg + i + 9, eol - i - 9);
+				return;
+			}
+		}
 		i = eol;
 	}
-	if (msg[i])
-		table[IBODY].value = xstrdup(msg + i);
-
-	len = interpolate(sb->buf + sb->len, strbuf_avail(sb),
-				format, table, ARRAY_SIZE(table));
-	if (len > strbuf_avail(sb)) {
-		strbuf_grow(sb, len);
-		interpolate(sb->buf + sb->len, strbuf_avail(sb) + 1,
-					format, table, ARRAY_SIZE(table));
-	}
-	strbuf_setlen(sb, sb->len + len);
-	interp_clear_table(table, ARRAY_SIZE(table));
+	if (msg[i] && placeholder[0] == 'b')	/* body */
+		strbuf_addstr(sb, msg + i);
+}
+
+void format_commit_message(const struct commit *commit,
+                           const void *format, struct strbuf *sb)
+{
+	const char *placeholders[] = {
+		"H",		/* commit hash */
+		"h",		/* abbreviated commit hash */
+		"T",		/* tree hash */
+		"t",		/* abbreviated tree hash */
+		"P",		/* parent hashes */
+		"p",		/* abbreviated parent hashes */
+		"an",		/* author name */
+		"ae",		/* author email */
+		"ad",		/* author date */
+		"aD",		/* author date, RFC2822 style */
+		"ar",		/* author date, relative */
+		"at",		/* author date, UNIX timestamp */
+		"ai",		/* author date, ISO 8601 */
+		"cn",		/* committer name */
+		"ce",		/* committer email */
+		"cd",		/* committer date */
+		"cD",		/* committer date, RFC2822 style */
+		"cr",		/* committer date, relative */
+		"ct",		/* committer date, UNIX timestamp */
+		"ci",		/* committer date, ISO 8601 */
+		"e",		/* encoding */
+		"s",		/* subject */
+		"b",		/* body */
+		"Cred",		/* red */
+		"Cgreen",	/* green */
+		"Cblue",	/* blue */
+		"Creset",	/* reset color */
+		"n",		/* newline */
+		"m",		/* left/right/bottom */
+		NULL
+	};
+	strbuf_expand(sb, format, placeholders, format_commit_item, (void *)commit);
 }
 
 static void pp_header(enum cmit_fmt fmt,
Previous: René ScharfeNext: Johannes Schindelin
Message 12 of 24 in “Make user formatted commit listing less expensive”
  1. 0/3 Make user formatted commit listing less expensiveJohannes Schindelin, Nov 4, 2007
  2. 1/3 Split off the pretty print stuff into its own fileJohannes Schindelin, Nov 4, 2007
  3. Junio C HamanoNov 5, 2007
  4. 2/3 interpolate.[ch]: Add a function to find which interpolations are active.Johannes Schindelin, Nov 4, 2007
  5. 3/3 pretty=format: Avoid some expensive calculations when not neededJohannes Schindelin, Nov 4, 2007
  6. Junio C HamanoNov 5, 2007
  7. René ScharfeNov 5, 2007
  8. Jon LoeligerNov 5, 2007
  9. Johannes SchindelinNov 5, 2007
  10. Junio C HamanoNov 6, 2007
  11. René ScharfeNov 6, 2007
  12. René ScharfeNov 6, 2007
  13. Johannes SchindelinNov 6, 2007
  14. René ScharfeNov 7, 2007
  15. Johannes SchindelinNov 8, 2007
  16. Pierre HabouzitNov 7, 2007
  17. Pierre HabouzitNov 7, 2007
  18. René ScharfeNov 7, 2007
  19. Pierre HabouzitNov 7, 2007
  20. Junio C HamanoNov 7, 2007
  21. René ScharfeNov 9, 2007
  22. Johannes SchindelinNov 6, 2007
  23. 1/2 interpolate.[ch]: Add a function to find which interpolations are active.Johannes Schindelin, Nov 6, 2007
  24. 2/2 pretty=format: Avoid some expensive calculations when not neededJohannes Schindelin, Nov 6, 2007

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