Make send/receive-pack be closer to doing something interesting

Makefile

@@ -9,7 +9,7 @@
 # BREAK YOUR LOCAL DIFFS! show-diff and anything using it will likely randomly
 # break unless your underlying filesystem supports those sub-second times
 # (my ext3 doesn't).
-COPTS=-O2
+COPTS=
 CFLAGS=-g $(COPTS) -Wall
 
 prefix=$(HOME)
@@ -46,9 +46,10 @@ install: $(PROG) $(SCRIPTS)
 
 LIB_OBJS=read-cache.o sha1_file.o usage.o object.o commit.o tree.o blob.o \
 	 tag.o date.o index.o diff-delta.o patch-delta.o entry.o \
-	 epoch.o refs.o csum-file.o verify_pack.o
+	 epoch.o refs.o csum-file.o verify_pack.o pkt-line.o
 LIB_FILE=libgit.a
-LIB_H=cache.h object.h blob.h tree.h commit.h tag.h delta.h epoch.h csum-file.h pack.h
+LIB_H=cache.h object.h blob.h tree.h commit.h tag.h delta.h epoch.h csum-file.h \
+	pack.h pkt-line.h
 
 LIB_H += strbuf.h
 LIB_OBJS += strbuf.o

pkt-line.c

@@ -0,0 +1,117 @@
+#include "cache.h"
+#include "pkt-line.h"
+
+/*
+ * Write a packetized stream, where each line is preceded by
+ * its length (including the header) as a 4-byte hex number.
+ * A length of 'zero' means end of stream (and a length of 1-3
+ * would be an error). 
+ *
+ * This is all pretty stupid, but we use this packetized line
+ * format to make a streaming format possible without ever
+ * over-running the read buffers. That way we'll never read
+ * into what might be the pack data (which should go to another
+ * process entirely).
+ *
+ * The writing side could use stdio, but since the reading
+ * side can't, we stay with pure read/write interfaces.
+ */
+static void safe_write(int fd, const void *buf, unsigned n)
+{
+	while (n) {
+		int ret = write(fd, buf, n);
+		if (ret > 0) {
+			buf += ret;
+			n -= ret;
+			continue;
+		}
+		if (!ret)
+			die("write error (disk full?)");
+		if (errno == EAGAIN || errno == EINTR)
+			continue;
+		die("write error (%s)", strerror(errno));
+	}
+}
+
+/*
+ * If we buffered things up above (we don't, but we should),
+ * we'd flush it here
+ */
+void packet_flush(int fd)
+{
+	safe_write(fd, "0000", 4);
+}
+
+#define hex(a) (hexchar[(a) & 15])
+void packet_write(int fd, const char *fmt, ...)
+{
+	static char buffer[1000];
+	static char hexchar[] = "0123456789abcdef";
+	va_list args;
+	unsigned n;
+
+	va_start(args, fmt);
+	n = vsnprintf(buffer + 4, sizeof(buffer) - 4, fmt, args);
+	va_end(args);
+	if (n >= sizeof(buffer)-4)
+		die("protocol error: impossibly long line");
+	n += 4;
+	buffer[0] = hex(n >> 12);
+	buffer[1] = hex(n >> 8);
+	buffer[2] = hex(n >> 4);
+	buffer[3] = hex(n);
+	safe_write(fd, buffer, n);
+}
+
+static void safe_read(int fd, void *buffer, unsigned size)
+{
+	int n = 0;
+
+	while (n < size) {
+		int ret = read(fd, buffer + n, size - n);
+		if (ret < 0) {
+			if (errno == EINTR || errno == EAGAIN)
+				continue;
+			die("read error (%s)", strerror(errno));
+		}
+		if (!ret)
+			die("unexpected EOF");
+		n += ret;
+	}
+}
+
+int packet_read_line(int fd, char *buffer, unsigned size)
+{
+	int n;
+	unsigned len;
+	char linelen[4];
+
+	safe_read(fd, linelen, 4);
+
+	len = 0;
+	for (n = 0; n < 4; n++) {
+		unsigned char c = linelen[n];
+		len <<= 4;
+		if (c >= '0' && c <= '9') {
+			len += c - '0';
+			continue;
+		}
+		if (c >= 'a' && c <= 'f') {
+			len += c - 'a' + 10;
+			continue;
+		}
+		if (c >= 'A' && c <= 'F') {
+			len += c - 'A' + 10;
+			continue;
+		}
+		die("protocol error: bad line length character");
+	}
+	if (!len)
+		return 0;
+	len -= 4;
+	if (len >= size)
+		die("protocol error: bad line length %d", len);
+	safe_read(fd, buffer, len);
+	buffer[len] = 0;
+	return len;
+}

pkt-line.h

@@ -0,0 +1,12 @@
+#ifndef PKTLINE_H
+#define PKTLINE_H
+
+/*
+ * Silly packetized line writing interface
+ */
+void packet_flush(int fd);
+void packet_write(int fd, const char *fmt, ...);
+
+int packet_read_line(int fd, char *buffer, unsigned size);
+
+#endif

receive-pack.c

@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "pkt-line.h"
 #include <sys/wait.h>
 
 static const char receive_pack_usage[] = "git-receive-pack [--unpack=executable] <git-dir> [heads]";
@@ -26,61 +27,9 @@ static int path_match(const char *path, int nr, char **match)
 	return 0;
 }
 
-static void safe_write(int fd, const void *buf, unsigned n)
-{
-	while (n) {
-		int ret = write(fd, buf, n);
-		if (ret > 0) {
-			buf += ret;
-			n -= ret;
-			continue;
-		}
-		if (!ret)
-			die("write error (disk full?)");
-		if (errno == EAGAIN || errno == EINTR)
-			continue;
-		die("write error (%s)", strerror(errno));
-	}
-}
-
-/*
- * If we buffered things up above (we don't, but we should),
- * we'd flush it here
- */
-static void flush_safe(int fd)
-{
-}
-
-/*
- * Write a packetized stream, where each line is preceded by
- * its length (including the header) as a 4-byte hex number.
- * A length of 'zero' means end of stream (and a length of 1-3
- * would be an error). 
- */
-#define hex(a) (hexchar[(a) & 15])
-static void packet_write(const char *fmt, ...)
-{
-	static char buffer[1000];
-	static char hexchar[] = "0123456789abcdef";
-	va_list args;
-	unsigned n;
-
-	va_start(args, fmt);
-	n = vsnprintf(buffer + 4, sizeof(buffer) - 4, fmt, args);
-	va_end(args);
-	if (n >= sizeof(buffer)-4)
-		die("protocol error: impossibly long line");
-	n += 4;
-	buffer[0] = hex(n >> 12);
-	buffer[1] = hex(n >> 8);
-	buffer[2] = hex(n >> 4);
-	buffer[3] = hex(n);
-	safe_write(1, buffer, n);
-}
-
 static void show_ref(const char *path, unsigned char *sha1)
 {
-	packet_write("%s %s\n", sha1_to_hex(sha1), path);
+	packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
 }
 
 static int read_ref(const char *path, unsigned char *sha1)
@@ -137,66 +86,6 @@ static void write_head_info(const char *base, int nr, char **match)
 	}
 }
 
-/*
- * This is all pretty stupid, but we use this packetized line
- * format to make a streaming format possible without ever
- * over-running the read buffers. That way we'll never read
- * into what might be the pack data (which should go to another
- * process entirely).
- *
- * The writing side could use stdio, but since the reading
- * side can't, we stay with pure read/write interfaces.
- */
-static void safe_read(int fd, void *buffer, unsigned size)
-{
-	int n = 0;
-
-	while (n < size) {
-		int ret = read(0, buffer + n, size - n);
-		if (ret < 0) {
-			if (errno == EINTR || errno == EAGAIN)
-				continue;
-			die("read error (%s)", strerror(errno));
-		}
-		if (!ret)
-			die("unexpected EOF");
-		n += ret;
-	}
-}
-
-static int safe_read_line(char *buffer, unsigned size)
-{
-	int n, len;
-
-	safe_read(0, buffer, 4);
-
-	len = 0;
-	for (n = 0; n < 4; n++) {
-		unsigned char c = buffer[n];
-		len <<= 4;
-		if (c >= '0' && c <= '9') {
-			len += c - '0';
-			continue;
-		}
-		if (c >= 'a' && c <= 'f') {
-			len += c - 'a' + 10;
-			continue;
-		}
-		if (c >= 'A' && c <= 'F') {
-			len += c - 'A' + 10;
-			continue;
-		}
-		die("protocol error: bad line length character");
-	}
-	if (!len)
-		return 0;
-	if (len < 4 || len >= size)
-		die("protocol error: bad line length %d", len);
-	safe_read(0, buffer + 4, len - 4);
-	buffer[len] = 0;
-	return len;
-}
-
 struct line {
 	struct line *next;
 	char data[0];
@@ -213,7 +102,7 @@ static void execute_commands(void)
 	struct line *line = commands;
 
 	while (line) {
-		printf("%s", line->data);
+		fprintf(stderr, "%s", line->data);
 		line = line->next;
 	}
 }
@@ -223,7 +112,7 @@ static void read_head_info(void)
 	struct line **p = &commands;
 	for (;;) {
 		static char line[1000];
-		int len = safe_read_line(line, sizeof(line));
+		int len = packet_read_line(0, line, sizeof(line));
 		struct line *n;
 		if (!len)
 			break;
@@ -242,8 +131,8 @@ static void unpack(void)
 	if (pid < 0)
 		die("unpack fork failed");
 	if (!pid) {
-		char *const envp[] = { "GIT_DIR=.", NULL };
-		execle(unpacker, unpacker, NULL, envp);
+		setenv("GIT_DIR", ".", 1);
+		execlp(unpacker, unpacker, NULL);
 		die("unpack execute failed");
 	}
 
@@ -311,8 +200,7 @@ int main(int argc, char **argv)
 	write_head_info("refs/", nr_heads, heads);
 
 	/* EOF */
-	safe_write(1, "0000", 4);
-	flush_safe(1);
+	packet_flush(1);
 
 	read_head_info();
 	unpack();

send-pack.c

@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "pkt-line.h"
 
 static const char send_pack_usage[] = "git-send-pack [--exec=other] destination [heads]*";
 
@@ -8,13 +9,16 @@ static int send_pack(int in, int out)
 {
 	for (;;) {
 		static char buffer[1000];
-		int ret = read(in, buffer, sizeof(buffer));
-		if (ret > 0) {
-			write(1, buffer, ret);
+		int len;
+
+		len = packet_read_line(in, buffer, sizeof(buffer));
+		if (len > 0) {
+			write(2, buffer, len);
 			continue;
 		}
 		break;
 	}
+	packet_flush(out);
 	close(out);
 	return 0;
 }
@@ -77,7 +81,7 @@ static int setup_connection(int fd[2], char *url, char **heads)
 		if (host)
 			execlp("ssh", "ssh", host, command, NULL);
 		else
-			execlp(host, command, NULL);
+			execlp("sh", "sh", "-c", command, NULL);
 		die("exec failed");
 	}		
 	fd[0] = pipefd[0][0];