1 files changed, 82 insertions, 0 deletions
diff --git a/pkt-line.h b/pkt-line.h
new file mode 100644
index 0000000000..3cb9d91baa
--- /dev/null
+++ b/pkt-line.h
@@ -0,0 +1,82 @@
+#ifndef PKTLINE_H
+#define PKTLINE_H
+
+#include "git-compat-util.h"
+#include "strbuf.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.
+ */
+void packet_flush(int fd);
+void packet_write(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
+void packet_buf_flush(struct strbuf *buf);
+void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
+
+/*
+ * Read a packetized line into the buffer, which must be at least size bytes
+ * long. The return value specifies the number of bytes read into the buffer.
+ *
+ * If src_buffer and *src_buffer are not NULL, it should point to a buffer
+ * containing the packet data to parse, of at least *src_len bytes.  After the
+ * function returns, src_buf will be incremented and src_len decremented by the
+ * number of bytes consumed.
+ *
+ * If src_buffer (or *src_buffer) is NULL, then data is read from the
+ * descriptor "fd".
+ *
+ * If options does not contain PACKET_READ_GENTLE_ON_EOF, we will die under any
+ * of the following conditions:
+ *
+ *   1. Read error from descriptor.
+ *
+ *   2. Protocol error from the remote (e.g., bogus length characters).
+ *
+ *   3. Receiving a packet larger than "size" bytes.
+ *
+ *   4. Truncated output from the remote (e.g., we expected a packet but got
+ *      EOF, or we got a partial packet followed by EOF).
+ *
+ * If options does contain PACKET_READ_GENTLE_ON_EOF, we will not die on
+ * condition 4 (truncated input), but instead return -1. However, we will still
+ * die for the other 3 conditions.
+ *
+ * If options contains PACKET_READ_CHOMP_NEWLINE, a trailing newline (if
+ * present) is removed from the buffer before returning.
+ */
+#define PACKET_READ_GENTLE_ON_EOF (1u<<0)
+#define PACKET_READ_CHOMP_NEWLINE (1u<<1)
+int packet_read(int fd, char **src_buffer, size_t *src_len, char
+		*buffer, unsigned size, int options);
+
+/*
+ * Convenience wrapper for packet_read that is not gentle, and sets the
+ * CHOMP_NEWLINE option. The return value is NULL for a flush packet,
+ * and otherwise points to a static buffer (that may be overwritten by
+ * subsequent calls). If the size parameter is not NULL, the length of the
+ * packet is written to it.
+ */
+char *packet_read_line(int fd, int *size);
+
+/*
+ * Same as packet_read_line, but read from a buf rather than a descriptor;
+ * see packet_read for details on how src_* is used.
+ */
+char *packet_read_line_buf(char **src_buf, size_t *src_len, int *size);
+
+#define DEFAULT_PACKET_MAX 1000
+#define LARGE_PACKET_MAX 65520
+extern char packet_buffer[LARGE_PACKET_MAX];
+
+#endif