Add stream helper library

This library provides thread-unsafe fgets()- and fread()-like
functions where the caller does not have to supply a buffer.  It
maintains a couple of static buffers and provides an API to use
them.

[rr: allow input from files other than stdin]
[jn: with tests, documentation, and error handling improvements]

Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/test-line-buffer.c b/test-line-buffer.c
new file mode 100644
index 0000000000..c11bf7f967
--- /dev/null
+++ b/test-line-buffer.c
@@ -0,0 +1,46 @@
+/*
+ * test-line-buffer.c: code to exercise the svn importer's input helper
+ *
+ * Input format:
+ *	number NL
+ *	(number bytes) NL
+ *	number NL
+ *	...
+ */
+
+#include "git-compat-util.h"
+#include "vcs-svn/line_buffer.h"
+
+static uint32_t strtouint32(const char *s)
+{
+	char *end;
+	uintmax_t n = strtoumax(s, &end, 10);
+	if (*s == '\0' || *end != '\0')
+		die("invalid count: %s", s);
+	return (uint32_t) n;
+}
+
+int main(int argc, char *argv[])
+{
+	char *s;
+
+	if (argc != 1)
+		usage("test-line-buffer < input.txt");
+	if (buffer_init(NULL))
+		die_errno("open error");
+	while ((s = buffer_read_line())) {
+		s = buffer_read_string(strtouint32(s));
+		fputs(s, stdout);
+		fputc('\n', stdout);
+		buffer_skip_bytes(1);
+		if (!(s = buffer_read_line()))
+			break;
+		buffer_copy_bytes(strtouint32(s) + 1);
+	}
+	if (buffer_deinit())
+		die("input error");
+	if (ferror(stdout))
+		die("output error");
+	buffer_reset();
+	return 0;
+}