Add string-specific memory pool

Intern strings so they can be compared by address and stored without
wasting space.

This library uses the macros in the obj_pool.h and trp.h to create a
memory pool for strings and expose an API for handling them.

[rr: added API docs]
[jn: with some API simplifications, new documentation and tests]

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, 31 insertions, 0 deletions

diff --git a/test-string-pool.c b/test-string-pool.c
new file mode 100644
index 000000000..c5782e6bc
--- /dev/null
+++ b/test-string-pool.c
@@ -0,0 +1,31 @@
+/*
+ * test-string-pool.c: code to exercise the svn importer's string pool
+ */
+
+#include "git-compat-util.h"
+#include "vcs-svn/string_pool.h"
+
+int main(int argc, char *argv[])
+{
+	const uint32_t unequal = pool_intern("does not equal");
+	const uint32_t equal = pool_intern("equals");
+	uint32_t buf[3];
+	uint32_t n;
+
+	if (argc != 2)
+		usage("test-string-pool <string>,<string>");
+
+	n = pool_tok_seq(3, buf, ",-", argv[1]);
+	if (n >= 3)
+		die("too many strings");
+	if (n <= 1)
+		die("too few strings");
+
+	buf[2] = buf[1];
+	buf[1] = (buf[0] == buf[2]) ? equal : unequal;
+	pool_print_seq(3, buf, ' ', stdout);
+	fputc('\n', stdout);
+
+	pool_reset();
+	return 0;
+}