Sometimes it is advantageous to be able to peek the next packet line
without consuming it (e.g. to be able to determine the protocol version
a server is speaking). In order to do that introduce 'struct
packet_reader' which is an abstraction around the normal packet reading
logic. This enables a caller to be able to peek a single line at a time
using 'packet_reader_peek()' and having a caller consume a line by
calling 'packet_reader_read()'.
Signed-off-by: Brandon Williams <bmw...@google.com>
---
pkt-line.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
pkt-line.h | 20 ++++++++++++++++++++
2 files changed, 81 insertions(+)
diff --git a/pkt-line.c b/pkt-line.c
index ac619f05b..518109bbe 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -406,3 +406,64 @@ ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf
*sb_out)
}
return sb_out->len - orig_len;
}
+
+/* Packet Reader Functions */
+void packet_reader_init(struct packet_reader *reader, int fd,
+ char *src_buffer, size_t src_len)
+{
+ reader->fd = fd;
+ reader->src_buffer = src_buffer;
+ reader->src_len = src_len;
+ reader->buffer = packet_buffer;
+ reader->buffer_size = sizeof(packet_buffer);
+ reader->options = PACKET_READ_CHOMP_NEWLINE | PACKET_READ_GENTLE_ON_EOF;
+
+ reader->line = NULL;
+ reader->line_peeked = 0;
+ reader->pktlen = 0;
+ reader->status = PACKET_READ_ERROR;
+}
+
+enum packet_read_status packet_reader_read(struct packet_reader *reader)
+{
+ if (reader->line_peeked) {
+ reader->line_peeked = 0;
+ return reader->status;
+ }
+
+ reader->status = packet_read_with_status(reader->fd,
+ &reader->src_buffer,
+ &reader->src_len,
+ reader->buffer,
+ reader->buffer_size,
+ &reader->pktlen,
+ reader->options);
+
+ switch (reader->status) {
+ case PACKET_READ_ERROR:
+ reader->pktlen = -1;
+ reader->line = NULL;
+ break;
+ case PACKET_READ_NORMAL:
+ reader->line = reader->buffer;
+ break;
+ case PACKET_READ_FLUSH:
+ reader->pktlen = 0;
+ reader->line = NULL;
+ break;
+ }
+
+ return reader->status;
+}
+
+enum packet_read_status packet_reader_peek(struct packet_reader *reader)
+{
+ /* Only allow peeking a single line */
+ if (reader->line_peeked)
+ return reader->status;
+
+ /* Peek a line by reading it and setting peeked flag */
+ packet_reader_read(reader);
+ reader->line_peeked = 1;
+ return reader->status;
+}
diff --git a/pkt-line.h b/pkt-line.h
index f1545929b..2b5c7cf11 100644
--- a/pkt-line.h
+++ b/pkt-line.h
@@ -104,6 +104,26 @@ char *packet_read_line_buf(char **src_buf, size_t
*src_len, int *size);
*/
ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out);
+struct packet_reader {
+ int fd;
+ char *src_buffer;
+ size_t src_len;
+
+ char *buffer;
+ unsigned buffer_size;
+ int options;
+
+ enum packet_read_status status;
+ int pktlen;
+ const char *line;
+ int line_peeked;
+};
+
+extern void packet_reader_init(struct packet_reader *reader, int fd,
+ char *src_buffer, size_t src_len);
+extern enum packet_read_status packet_reader_read(struct packet_reader
*reader);
+extern enum packet_read_status packet_reader_peek(struct packet_reader
*reader);
+
#define DEFAULT_PACKET_MAX 1000
#define LARGE_PACKET_MAX 65520
#define LARGE_PACKET_DATA_MAX (LARGE_PACKET_MAX - 4)
--
2.15.1.424.g9478a66081-goog
