Introduce internal Log class that handles writing log messages, enable logging to memory buffer.

test/cctest/test-log.cc

Index: test/cctest/test-log.cc
diff --git a/test/cctest/test-log.cc b/test/cctest/test-log.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0370cbec45196ed67ea1cd790366f40bd996e943
--- /dev/null
+++ b/test/cctest/test-log.cc
@@ -0,0 +1,102 @@
+// Copyright 2006-2009 the V8 project authors. All rights reserved.
+//
+// Tests of logging functions from log.h
+
+#ifdef ENABLE_LOGGING_AND_PROFILING
+
+#include "v8.h"
+
+#include "log.h"
+
+#include "cctest.h"
+
+using v8::internal::Logger;
+
+static void SetUp() {
+  // Log to memory buffer.
+  v8::internal::FLAG_logfile = "*";
+  v8::internal::FLAG_log = true;
+  Logger::Setup();
+}
+
+static void TearDown() {
+  Logger::TearDown();
+}
+
+TEST(EmptyLog) {
+  SetUp();
+  CHECK_EQ(0, Logger::GetLogLines(0, NULL, 0));
+  CHECK_EQ(0, Logger::GetLogLines(100, NULL, 0));
+  CHECK_EQ(0, Logger::GetLogLines(0, NULL, 100));
+  CHECK_EQ(0, Logger::GetLogLines(100, NULL, 100));
+  TearDown();
+}
+
+
+TEST(GetMessages) {
+  SetUp();
+  Logger::StringEvent("aaa", "bbb");
+  Logger::StringEvent("cccc", "dddd");
+  CHECK_EQ(0, Logger::GetLogLines(0, NULL, 0));
+  char log_lines[100];
+  memset(log_lines, 0, sizeof(log_lines));
+  // Requesting data size which is smaller than first log message length.
+  CHECK_EQ(0, Logger::GetLogLines(0, log_lines, 3));
+  // See Logger::StringEvent.
+  const char* line_1 = "aaa,\"bbb\"\n";
+  const int line_1_len = strlen(line_1);
+  // Still smaller than log message length.
+  CHECK_EQ(0, Logger::GetLogLines(0, log_lines, line_1_len - 1));
+  // The exact size.
+  CHECK_EQ(line_1_len, Logger::GetLogLines(0, log_lines, line_1_len));
+  CHECK_EQ(line_1, log_lines);
+  memset(log_lines, 0, sizeof(log_lines));
+  // A bit more than the first line length.
+  CHECK_EQ(line_1_len, Logger::GetLogLines(0, log_lines, line_1_len + 3));
+  CHECK_EQ(line_1, log_lines);
+  memset(log_lines, 0, sizeof(log_lines));
+  const char* line_2 = "cccc,\"dddd\"\n";
+  const int line_2_len = strlen(line_2);
+  // Now start with line_2 beginning.
+  CHECK_EQ(0, Logger::GetLogLines(line_1_len, log_lines, 0));
+  CHECK_EQ(0, Logger::GetLogLines(line_1_len, log_lines, 3));
+  CHECK_EQ(0, Logger::GetLogLines(line_1_len, log_lines, line_2_len - 1));
+  CHECK_EQ(line_2_len, Logger::GetLogLines(line_1_len, log_lines, line_2_len));
+  CHECK_EQ(line_2, log_lines);
+  memset(log_lines, 0, sizeof(log_lines));
+  CHECK_EQ(line_2_len,
+           Logger::GetLogLines(line_1_len, log_lines, line_2_len + 3));
+  CHECK_EQ(line_2, log_lines);
+  memset(log_lines, 0, sizeof(log_lines));
+  // Now get entire buffer contents.
+  const char* all_lines = "aaa,\"bbb\"\ncccc,\"dddd\"\n";
+  const int all_lines_len = strlen(all_lines);
+  CHECK_EQ(all_lines_len, Logger::GetLogLines(0, log_lines, all_lines_len));
+  CHECK_EQ(all_lines, log_lines);
+  memset(log_lines, 0, sizeof(log_lines));
+  CHECK_EQ(all_lines_len, Logger::GetLogLines(0, log_lines, all_lines_len + 3));
+  CHECK_EQ(all_lines, log_lines);
+  memset(log_lines, 0, sizeof(log_lines));
+  TearDown();
+}
+
+
+TEST(BeyondWritePosition) {
+  SetUp();
+  Logger::StringEvent("aaa", "bbb");
+  Logger::StringEvent("cccc", "dddd");
+  // See Logger::StringEvent.
+  const char* all_lines = "aaa,\"bbb\"\ncccc,\"dddd\"\n";
+  const int all_lines_len = strlen(all_lines);
+  CHECK_EQ(0, Logger::GetLogLines(all_lines_len, NULL, 1));
+  CHECK_EQ(0, Logger::GetLogLines(all_lines_len, NULL, 100));
+  CHECK_EQ(0, Logger::GetLogLines(all_lines_len + 1, NULL, 1));
+  CHECK_EQ(0, Logger::GetLogLines(all_lines_len + 1, NULL, 100));
+  CHECK_EQ(0, Logger::GetLogLines(all_lines_len + 100, NULL, 1));
+  CHECK_EQ(0, Logger::GetLogLines(all_lines_len + 100, NULL, 100));
+  CHECK_EQ(0, Logger::GetLogLines(10 * 1024 * 1024, NULL, 1));
+  CHECK_EQ(0, Logger::GetLogLines(10 * 1024 * 1024, NULL, 100));
+  TearDown();
+}
+
+#endif  // ENABLE_LOGGING_AND_PROFILING