1 files changed, 205 insertions, 0 deletions

diff --git a/tests/t_buf.c b/tests/t_buf.c
new file mode 100644
index 0000000..dcfb0bb
--- /dev/null
+++ b/tests/t_buf.c
@@ -0,0 +1,205 @@
+/* This software was written by Dirk Engling <erdgeist@erdgeist.org>
+   It is considered beerware. Prost. Skol. Cheers or whatever.
+
+   $id$ */
+
+/* System */
+#include <stdint.h>
+#include <string.h>
+
+/* Opentracker */
+#include "ot_buf.h"
+#include "test.h"
+
+static void case_starts_empty(void) {
+  ot_buf buf = {NULL, 0};
+
+  test_case("a fresh buffer holds nothing and has no data pointer");
+  CHECK_PTR(buf.data, NULL);
+  CHECK_INT(buf.size, 0);
+}
+
+static void case_cat_appends(void) {
+  ot_buf buf = {NULL, 0};
+
+  test_case("appends concatenate in order and report success");
+  CHECK_INT(buf_cat(&buf, "GET /ann", 8), 0);
+  CHECK(buf.data != NULL);
+  CHECK_INT(buf.size, 8);
+  CHECK_INT(buf_cat(&buf, "ounce", 5), 0);
+  CHECK_INT(buf.size, 13);
+  CHECK_MEM(buf.data, "GET /announce", 13);
+  buf_reset(&buf);
+}
+
+static void case_cat_of_nothing_allocates_nothing(void) {
+  ot_buf buf = {NULL, 0};
+
+  /* handle_read tells an untouched buffer from a partial request by the data
+     pointer, so a zero length append must not quietly allocate one */
+  test_case("appending zero bytes leaves the buffer untouched");
+  CHECK_INT(buf_cat(&buf, "ignored", 0), 0);
+  CHECK_PTR(buf.data, NULL);
+  CHECK_INT(buf.size, 0);
+  buf_reset(&buf);
+}
+
+static void case_grows_across_many_appends(void) {
+  ot_buf buf = {NULL, 0};
+  char   chunk[100];
+  size_t i;
+
+  test_case("content survives growing one packet at a time");
+  memset(chunk, 'x', sizeof(chunk));
+  for (i = 0; i < 100; ++i)
+    if (buf_cat(&buf, chunk, sizeof(chunk))) {
+      test_failf(__FILE__, __LINE__, "append %zu was refused", i);
+      buf_reset(&buf);
+      return;
+    }
+  ++test_checks;
+  CHECK_INT(buf.size, 10000);
+  for (i = 0; i < 10000; ++i)
+    if (buf.data[i] != 'x') {
+      test_failf(__FILE__, __LINE__, "byte %zu was not preserved across growth", i);
+      buf_reset(&buf);
+      return;
+    }
+  ++test_checks;
+  buf_reset(&buf);
+}
+
+static void case_grows_one_byte_at_a_time(void) {
+  ot_buf buf = {NULL, 0};
+  size_t i;
+
+  /* The shape a trickling client produces. Nothing here is optimised for it,
+     so the point is only that it stays correct. */
+  test_case("a byte at a time accumulates correctly");
+  for (i = 0; i < 2048; ++i) {
+    char c = (char)('a' + (i % 26));
+    if (buf_cat(&buf, &c, 1)) {
+      test_failf(__FILE__, __LINE__, "append %zu was refused", i);
+      buf_reset(&buf);
+      return;
+    }
+  }
+  ++test_checks;
+  CHECK_INT(buf.size, 2048);
+  for (i = 0; i < 2048; ++i)
+    if (buf.data[i] != (char)('a' + (i % 26))) {
+      test_failf(__FILE__, __LINE__, "byte %zu differs", i);
+      buf_reset(&buf);
+      return;
+    }
+  ++test_checks;
+  buf_reset(&buf);
+}
+
+static void case_truncate_shrinks_only(void) {
+  ot_buf buf = {NULL, 0};
+
+  test_case("truncate drops the tail but never grows");
+  buf_cat(&buf, "0123456789", 10);
+  buf_truncate(&buf, 4);
+  CHECK_INT(buf.size, 4);
+  CHECK_MEM(buf.data, "0123", 4);
+
+  buf_truncate(&buf, 9);
+  CHECK_INT(buf.size, 4);
+  buf_truncate(&buf, 4);
+  CHECK_INT(buf.size, 4);
+
+  buf_truncate(&buf, 0);
+  CHECK_INT(buf.size, 0);
+  buf_reset(&buf);
+}
+
+static void case_append_after_truncate(void) {
+  ot_buf buf = {NULL, 0};
+
+  test_case("appending after a truncate overwrites the dropped tail");
+  buf_cat(&buf, "keepdrop", 8);
+  buf_truncate(&buf, 4);
+  CHECK_INT(buf_cat(&buf, "MORE", 4), 0);
+  CHECK_INT(buf.size, 8);
+  CHECK_MEM(buf.data, "keepMORE", 8);
+  buf_reset(&buf);
+}
+
+static void case_reset_clears_everything(void) {
+  ot_buf buf = {NULL, 0};
+
+  test_case("reset releases the buffer and restores the initial state");
+  buf_cat(&buf, "something", 9);
+  buf_reset(&buf);
+  CHECK_PTR(buf.data, NULL);
+  CHECK_INT(buf.size, 0);
+}
+
+static void case_reset_of_empty_is_safe(void) {
+  ot_buf buf = {NULL, 0};
+
+  test_case("resetting a buffer that was never used is harmless");
+  buf_reset(&buf);
+  buf_reset(&buf);
+  CHECK_PTR(buf.data, NULL);
+  CHECK_INT(buf.size, 0);
+}
+
+static void case_refused_append_is_harmless(void) {
+  ot_buf buf = {NULL, 0};
+
+  /* A length that would wrap the size is rejected before src is read and
+     before anything is allocated, so a short string is safe to pass here.
+     A refused append must not destroy the partial request already collected:
+     the caller answers and closes rather than losing both. */
+  test_case("a length that would wrap the size is refused");
+  CHECK_INT(buf_cat(&buf, "already here", 12), 0);
+  CHECK_INT(buf_cat(&buf, "x", (size_t)-1), -1);
+
+  test_case("and earlier content survives it");
+  CHECK_INT(buf.size, 12);
+  CHECK_MEM(buf.data, "already here", 12);
+
+  test_case("and the buffer still works afterwards");
+  CHECK_INT(buf_cat(&buf, "!", 1), 0);
+  CHECK_INT(buf.size, 13);
+  CHECK_MEM(buf.data, "already here!", 13);
+  buf_reset(&buf);
+}
+
+static void case_accumulates_a_split_request(void) {
+  /* What handle_read actually does: collect a request that arrived in
+     pieces, then hand over the whole of it */
+  ot_buf      buf      = {NULL, 0};
+  const char *pieces[] = {"GET /announce?info_hash=", "0123456789abcdefghij", " HTTP/1.0\r\n\r\n"};
+  size_t      i;
+
+  test_case("a request split over several reads is reassembled");
+  for (i = 0; i < 3; ++i)
+    if (buf_cat(&buf, pieces[i], strlen(pieces[i]))) {
+      test_failf(__FILE__, __LINE__, "piece %zu was refused", i);
+      buf_reset(&buf);
+      return;
+    }
+  ++test_checks;
+
+  CHECK_INT(buf.size, 24 + 20 + 13);
+  CHECK_MEM(buf.data, "GET /announce?info_hash=0123456789abcdefghij HTTP/1.0\r\n\r\n", 57);
+  buf_reset(&buf);
+}
+
+void test_buf(void) {
+  case_starts_empty();
+  case_cat_appends();
+  case_cat_of_nothing_allocates_nothing();
+  case_grows_across_many_appends();
+  case_grows_one_byte_at_a_time();
+  case_truncate_shrinks_only();
+  case_append_after_truncate();
+  case_reset_clears_everything();
+  case_reset_of_empty_is_safe();
+  case_refused_append_is_harmless();
+  case_accumulates_a_split_request();
+}