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From: larsxschneider@gmail.com
To: git@vger.kernel.org
Cc: peff@peff.net, gitster@pobox.com, sbeller@google.com,
	Johannes.Schindelin@gmx.de, jnareb@gmail.com, mlbright@gmail.com,
	Lars Schneider <larsxschneider@gmail.com>
Subject: [PATCH v6 06/13] pkt-line: add functions to read/write flush terminated packet streams
Date: Thu, 25 Aug 2016 13:07:45 +0200	[thread overview]
Message-ID: <20160825110752.31581-7-larsxschneider@gmail.com> (raw)
In-Reply-To: <20160825110752.31581-1-larsxschneider@gmail.com>

From: Lars Schneider <larsxschneider@gmail.com>

packet_write_stream_with_flush_from_fd() and
packet_write_stream_with_flush_from_buf() write a stream of packets. All
content packets use the maximal packet size except for the last one.
After the last content packet a `flush` control packet is written.

packet_read_till_flush() reads arbitrary sized packets until it detects
a `flush` packet.

Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
---
 pkt-line.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 pkt-line.h |  7 +++++
 2 files changed, 98 insertions(+)

diff --git a/pkt-line.c b/pkt-line.c
index 7e8a803..3033aa3 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -176,6 +176,47 @@ void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
 	va_end(args);
 }
 
+int packet_write_stream_with_flush_from_fd(int fd_in, int fd_out)
+{
+	int err = 0;
+	ssize_t bytes_to_write;
+
+	while (!err) {
+		bytes_to_write = xread(fd_in, packet_write_buffer, sizeof(packet_write_buffer) - 4);
+		if (bytes_to_write < 0)
+			return COPY_READ_ERROR;
+		if (bytes_to_write == 0)
+			break;
+		if (bytes_to_write > sizeof(packet_write_buffer) - 4)
+			return COPY_WRITE_ERROR;
+		err = packet_write_gently(fd_out, packet_write_buffer, bytes_to_write);
+	}
+	if (!err)
+		err = packet_flush_gently(fd_out);
+	return err;
+}
+
+int packet_write_stream_with_flush_from_buf(const char *src_in, size_t len, int fd_out)
+{
+	int err = 0;
+	size_t bytes_written = 0;
+	size_t bytes_to_write;
+
+	while (!err) {
+		if ((len - bytes_written) > sizeof(packet_write_buffer) - 4)
+			bytes_to_write = sizeof(packet_write_buffer) - 4;
+		else
+			bytes_to_write = len - bytes_written;
+		if (bytes_to_write == 0)
+			break;
+		err = packet_write_gently(fd_out, src_in + bytes_written, bytes_to_write);
+		bytes_written += bytes_to_write;
+	}
+	if (!err)
+		err = packet_flush_gently(fd_out);
+	return err;
+}
+
 static int get_packet_data(int fd, char **src_buf, size_t *src_size,
 			   void *dst, unsigned size, int options)
 {
@@ -285,3 +326,53 @@ char *packet_read_line_buf(char **src, size_t *src_len, int *dst_len)
 {
 	return packet_read_line_generic(-1, src, src_len, dst_len);
 }
+
+ssize_t packet_read_till_flush(int fd_in, struct strbuf *sb_out)
+{
+	int len, ret;
+	int options = PACKET_READ_GENTLE_ON_EOF;
+	char linelen[4];
+
+	size_t oldlen = sb_out->len;
+	size_t oldalloc = sb_out->alloc;
+
+	for (;;) {
+		/* Read packet header */
+		ret = get_packet_data(fd_in, NULL, NULL, linelen, 4, options);
+		if (ret < 0)
+			goto done;
+		len = packet_length(linelen);
+		if (len < 0)
+			die("protocol error: bad line length character: %.4s", linelen);
+		if (!len) {
+			/* Found a flush packet - Done! */
+			packet_trace("0000", 4, 0);
+			break;
+		}
+		len -= 4;
+
+		/* Read packet content */
+		strbuf_grow(sb_out, len);
+		ret = get_packet_data(fd_in, NULL, NULL, sb_out->buf + sb_out->len, len, options);
+		if (ret < 0)
+			goto done;
+
+		if (ret != len) {
+			error("protocol error: incomplete read (expected %d, got %d)", len, ret);
+			goto done;
+		}
+
+		packet_trace(sb_out->buf + sb_out->len, len, 0);
+		sb_out->len += len;
+	}
+
+done:
+	if (ret < 0) {
+		if (oldalloc == 0)
+			strbuf_release(sb_out);
+		else
+			strbuf_setlen(sb_out, oldlen);
+		return ret;  /* unexpected EOF */
+	}
+	return sb_out->len - oldlen;
+}
diff --git a/pkt-line.h b/pkt-line.h
index 3fa0899..9616117 100644
--- a/pkt-line.h
+++ b/pkt-line.h
@@ -25,6 +25,8 @@ void packet_buf_flush(struct strbuf *buf);
 void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
 int packet_flush_gently(int fd);
 int packet_write_fmt_gently(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
+int packet_write_stream_with_flush_from_fd(int fd_in, int fd_out);
+int packet_write_stream_with_flush_from_buf(const char *src_in, size_t len, int fd_out);
 
 /*
  * Read a packetized line into the buffer, which must be at least size bytes
@@ -77,6 +79,11 @@ char *packet_read_line(int fd, int *size);
  */
 char *packet_read_line_buf(char **src_buf, size_t *src_len, int *size);
 
+/*
+ * Reads a stream of variable sized packets until a flush packet is detected.
+ */
+ssize_t packet_read_till_flush(int fd_in, struct strbuf *sb_out);
+
 #define DEFAULT_PACKET_MAX 1000
 #define LARGE_PACKET_MAX 65520
 extern char packet_buffer[LARGE_PACKET_MAX];
-- 
2.9.2


  parent reply	other threads:[~2016-08-25 11:19 UTC|newest]

Thread overview: 66+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-25 11:07 [PATCH v6 00/13] Git filter protocol larsxschneider
2016-08-25 11:07 ` [PATCH v6 01/13] pkt-line: rename packet_write() to packet_write_fmt() larsxschneider
2016-08-25 11:07 ` [PATCH v6 02/13] pkt-line: extract set_packet_header() larsxschneider
2016-08-25 11:07 ` [PATCH v6 03/13] pkt-line: add packet_write_fmt_gently() larsxschneider
2016-08-25 18:12   ` Stefan Beller
2016-08-25 18:47     ` Lars Schneider
2016-08-25 21:41   ` Junio C Hamano
2016-08-26  9:17     ` Lars Schneider
2016-08-26 17:10       ` Junio C Hamano
2016-08-26 17:23         ` Jeff King
2016-08-25 11:07 ` [PATCH v6 04/13] pkt-line: add packet_flush_gently() larsxschneider
2016-08-25 11:07 ` [PATCH v6 05/13] pkt-line: add packet_write_gently() larsxschneider
2016-08-25 21:50   ` Junio C Hamano
2016-08-26  9:40     ` Lars Schneider
2016-08-26 17:15       ` Junio C Hamano
2016-08-29  9:40         ` Lars Schneider
2016-08-25 11:07 ` larsxschneider [this message]
2016-08-25 18:46   ` [PATCH v6 06/13] pkt-line: add functions to read/write flush terminated packet streams Stefan Beller
2016-08-25 19:33     ` Lars Schneider
2016-08-25 22:31     ` Junio C Hamano
2016-08-26  0:55       ` Jacob Keller
2016-08-26 17:02         ` Stefan Beller
2016-08-26 17:21           ` Jeff King
2016-08-26 17:17         ` Junio C Hamano
2016-08-25 22:27   ` Junio C Hamano
2016-08-26 10:13     ` Lars Schneider
2016-08-26 17:21       ` Junio C Hamano
2016-08-29  9:43         ` Lars Schneider
2016-08-25 11:07 ` [PATCH v6 07/13] pack-protocol: fix maximum pkt-line size larsxschneider
2016-08-25 18:59   ` Stefan Beller
2016-08-25 19:35     ` Lars Schneider
2016-08-26 19:44       ` Junio C Hamano
2016-08-25 11:07 ` [PATCH v6 08/13] convert: quote filter names in error messages larsxschneider
2016-08-26 19:45   ` Junio C Hamano
2016-08-25 11:07 ` [PATCH v6 09/13] convert: modernize tests larsxschneider
2016-08-26 20:03   ` Junio C Hamano
2016-08-29 10:09     ` Lars Schneider
2016-08-25 11:07 ` [PATCH v6 10/13] convert: generate large test files only once larsxschneider
2016-08-25 19:17   ` Stefan Beller
2016-08-25 19:54     ` Lars Schneider
2016-08-29 17:52       ` Junio C Hamano
2016-08-30 11:47         ` Lars Schneider
2016-08-30 16:55           ` Junio C Hamano
2016-08-29 17:46   ` Junio C Hamano
2016-08-30 11:41     ` Lars Schneider
2016-08-30 16:37       ` Jeff King
2016-08-25 11:07 ` [PATCH v6 11/13] convert: make apply_filter() adhere to standard Git error handling larsxschneider
2016-08-25 11:07 ` [PATCH v6 12/13] convert: add filter.<driver>.process option larsxschneider
2016-08-29 22:21   ` Junio C Hamano
2016-08-30 16:27     ` Lars Schneider
2016-08-30 18:59       ` Junio C Hamano
2016-08-30 20:38         ` Lars Schneider
2016-08-30 22:23           ` Junio C Hamano
2016-08-31  4:57             ` Torsten Bögershausen
2016-08-31 13:14               ` Jakub Narębski
2016-08-30 20:46         ` Jakub Narębski
2016-09-05 19:47           ` Lars Schneider
2016-08-25 11:07 ` [PATCH v6 13/13] read-cache: make sure file handles are not inherited by child processes larsxschneider
2016-08-29 18:05   ` Junio C Hamano
2016-08-29 19:03     ` Lars Schneider
2016-08-29 19:45       ` Junio C Hamano
2016-08-30 12:32         ` Lars Schneider
2016-08-30 14:54           ` Torsten Bögershausen
2016-09-01 17:15             ` Junio C Hamano
2016-08-29 15:39 ` [PATCH v6 00/13] Git filter protocol Lars Schneider
2016-08-29 18:09   ` Junio C Hamano

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