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authorAndreas Baumann <abaumann@yahoo.com>2012-08-04 14:01:19 +0200
committerAndreas Baumann <abaumann@yahoo.com>2012-08-04 14:01:19 +0200
commit9473c0bb8d1a69a042e1fd745fb2f76ea0b8ac27 (patch)
treef88532f9adc9d15514f484cdf65e21c78d72e480 /googleurl/base/logging.h
parent4029e28c299049e19972556eeb22cf6d15147eab (diff)
downloadcrawler-9473c0bb8d1a69a042e1fd745fb2f76ea0b8ac27.tar.gz
crawler-9473c0bb8d1a69a042e1fd745fb2f76ea0b8ac27.tar.bz2
added google url library
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+// Copyright 2006 Google Inc. All Rights Reserved.
+// Author: brettw (Brett Wilson)
+
+#ifndef BASE_LOGGING_H__
+#define BASE_LOGGING_H__
+
+#include <string>
+#include <cstring>
+#include <sstream>
+#ifdef _WIN32
+#include <tchar.h>
+#endif
+
+#include "base/basictypes.h"
+#include "base/scoped_ptr.h"
+
+// Optional message capabilities
+// -----------------------------
+// Assertion failed messages and fatal errors are displayed in a dialog box
+// before the application exits. However, running this UI creates a message
+// loop, which causes application messages to be processed and potentially
+// dispatched to existing application windows. Since the application is in a
+// bad state when this assertion dialog is displayed, these messages may not
+// get processed and hang the dialog, or the application might go crazy.
+//
+// Therefore, it can be beneficial to display the error dialog in a separate
+// process from the main application. When the logging system needs to display
+// a fatal error dialog box, it will look for a program called
+// "DebugMessage.exe" in the same directory as the application executable. It
+// will run this application with the message as the command line, and will
+// not include the name of the application as is traditional for easier
+// parsing.
+//
+// The code for DebugMessage.exe is only one line. In WinMain, do:
+// MessageBox(NULL, GetCommandLineW(), L"Fatal Error", 0);
+//
+// If DebugMessage.exe is not found, the logging code will use a normal
+// MessageBox, potentially causing the problems discussed above.
+
+
+// Instructions
+// ------------
+//
+// Make a bunch of macros for logging. The way to log things is to stream
+// things to LOG(<a particular severity level>). E.g.,
+//
+// LOG(INFO) << "Found " << num_cookies << " cookies";
+//
+// You can also do conditional logging:
+//
+// LOG_IF(INFO, num_cookies > 10) << "Got lots of cookies";
+//
+// The above will cause log messages to be output on the 1st, 11th, 21st, ...
+// times it is executed. Note that the special COUNTER value is used to
+// identify which repetition is happening.
+//
+// There are also "debug mode" logging macros like the ones above:
+//
+// DLOG(INFO) << "Found cookies";
+//
+// DLOG_IF(INFO, num_cookies > 10) << "Got lots of cookies";
+//
+// All "debug mode" logging is compiled away to nothing for non-debug mode
+// compiles. LOG_IF and development flags also work well together
+// because the code can be compiled away sometimes.
+//
+// We also have
+//
+// LOG_ASSERT(assertion);
+// DLOG_ASSERT(assertion);
+//
+// which is syntactic sugar for {,D}LOG_IF(FATAL, assert fails) << assertion;
+//
+// We also override the standard 'assert' to use 'DLOG_ASSERT'.
+//
+// The supported severity levels for macros that allow you to specify one
+// are (in increasing order of severity) INFO, WARNING, ERROR, and FATAL.
+//
+// There is also the special severity of DFATAL, which logs FATAL in
+// debug mode, ERROR in normal mode.
+//
+// Very important: logging a message at the FATAL severity level causes
+// the program to terminate (after the message is logged).
+
+namespace logging {
+
+// Where to record logging output? A flat file and/or system debug log via
+// OutputDebugString. Defaults to LOG_ONLY_TO_FILE.
+enum LoggingDestination { LOG_ONLY_TO_FILE,
+ LOG_ONLY_TO_SYSTEM_DEBUG_LOG,
+ LOG_TO_BOTH_FILE_AND_SYSTEM_DEBUG_LOG };
+
+// Indicates that the log file should be locked when being written to.
+// Often, there is no locking, which is fine for a single threaded program.
+// If logging is being done from multiple threads or there can be more than
+// one process doing the logging, the file should be locked during writes to
+// make each log outut atomic. Other writers will block.
+//
+// All processes writing to the log file must have their locking set for it to
+// work properly. Defaults to DONT_LOCK_LOG_FILE.
+enum LogLockingState { LOCK_LOG_FILE, DONT_LOCK_LOG_FILE };
+
+// On startup, should we delete or append to an existing log file (if any)?
+// Defaults to APPEND_TO_OLD_LOG_FILE.
+enum OldFileDeletionState { DELETE_OLD_LOG_FILE, APPEND_TO_OLD_LOG_FILE };
+
+// Sets the log file name and other global logging state. Calling this function
+// is recommended, and is normally done at the beginning of application init.
+// If you don't call it, all the flags will be initialized to their default
+// values, and there is a race condition that may leak a critical section
+// object if two threads try to do the first log at the same time.
+// See the definition of the enums above for descriptions and default values.
+//
+// The default log file is initialized to "debug.log" in the application
+// directory. You probably don't want this, especially since the program
+// directory may not be writable on an enduser's system.
+#ifdef _WIN32
+void InitLogging(const TCHAR* log_file, LoggingDestination logging_dest,
+ LogLockingState lock_log, OldFileDeletionState delete_old);
+#else
+void InitLogging(const char* log_file, LoggingDestination logging_dest,
+ LogLockingState lock_log, OldFileDeletionState delete_old);
+#endif
+
+// Sets the log level. Anything at or above this level will be written to the
+// log file/displayed to the user (if applicable). Anything below this level
+// will be silently ignored. The log level defaults to 0 (everything is logged)
+// if this function is not called.
+void SetMinLogLevel(int level);
+
+// Sets the log filter prefix. Any log message below LOG_ERROR severity that
+// doesn't start with this prefix with be silently ignored. The filter defaults
+// to NULL (everything is logged) if this function is not called. Messages
+// with severity of LOG_ERROR or higher will not be filtered.
+void SetLogFilterPrefix(char* filter);
+
+// Sets the common items you want to be prepended to each log message.
+// process and thread IDs default to off, the timestamp defaults to on.
+// If this function is not called, logging defaults to writing the timestamp
+// only.
+void SetLogItems(bool enable_process_id, bool enable_thread_id,
+ bool enable_timestamp, bool enable_tickcount);
+
+// Sets the Log Assert Handler that will be used to notify of check failures.
+// The default handler shows a dialog box, however clients can use this
+// function to override with their own handling (e.g. a silent one for Unit
+// Tests)
+typedef void (*LogAssertHandlerFunction)(const std::string& str);
+void SetLogAssertHandler(LogAssertHandlerFunction handler);
+
+typedef int LogSeverity;
+const LogSeverity LOG_INFO = 0;
+const LogSeverity LOG_WARNING = 1;
+const LogSeverity LOG_ERROR = 2;
+const LogSeverity LOG_FATAL = 3;
+const LogSeverity LOG_NUM_SEVERITIES = 4;
+
+// LOG_DFATAL_LEVEL is LOG_FATAL in debug mode, ERROR in normal mode
+#ifdef NDEBUG
+const LogSeverity LOG_DFATAL_LEVEL = LOG_ERROR;
+#else
+const LogSeverity LOG_DFATAL_LEVEL = LOG_FATAL;
+#endif
+
+// A few definitions of macros that don't generate much code. These are used
+// by LOG() and LOG_IF, etc. Since these are used all over our code, it's
+// better to have compact code for these operations.
+#define COMPACT_GOOGLE_LOG_INFO \
+ logging::LogMessage(__FILE__, __LINE__)
+#define COMPACT_GOOGLE_LOG_WARNING \
+ logging::LogMessage(__FILE__, __LINE__, logging::LOG_WARNING)
+#define COMPACT_GOOGLE_LOG_ERROR \
+ logging::LogMessage(__FILE__, __LINE__, logging::LOG_ERROR)
+#define COMPACT_GOOGLE_LOG_FATAL \
+ logging::LogMessage(__FILE__, __LINE__, logging::LOG_FATAL)
+#define COMPACT_GOOGLE_LOG_DFATAL \
+ logging::LogMessage(__FILE__, __LINE__, logging::LOG_DFATAL_LEVEL)
+
+// wingdi.h defines ERROR to be 0. When we call LOG(ERROR), it gets
+// substituted with 0, and it expands to COMPACT_GOOGLE_LOG_0. To allow us
+// to keep using this syntax, we define this macro to do the same thing
+// as COMPACT_GOOGLE_LOG_ERROR, and also define ERROR the same way that
+// the Windows SDK does for consistency.
+#define ERROR 0
+#define COMPACT_GOOGLE_LOG_0 \
+ logging::LogMessage(__FILE__, __LINE__, logging::LOG_ERROR)
+
+// We use the preprocessor's merging operator, "##", so that, e.g.,
+// LOG(INFO) becomes the token COMPACT_GOOGLE_LOG_INFO. There's some funny
+// subtle difference between ostream member streaming functions (e.g.,
+// ostream::operator<<(int) and ostream non-member streaming functions
+// (e.g., ::operator<<(ostream&, string&): it turns out that it's
+// impossible to stream something like a string directly to an unnamed
+// ostream. We employ a neat hack by calling the stream() member
+// function of LogMessage which seems to avoid the problem.
+
+#define LOG(severity) COMPACT_GOOGLE_LOG_ ## severity.stream()
+#define SYSLOG(severity) LOG(severity)
+
+#define LOG_IF(severity, condition) \
+ !(condition) ? (void) 0 : logging::LogMessageVoidify() & LOG(severity)
+#define SYSLOG_IF(severity, condition) LOG_IF(severity, condition)
+
+#define LOG_ASSERT(condition) \
+ LOG_IF(FATAL, !(condition)) << "Assert failed: " #condition ". "
+#define SYSLOG_ASSERT(condition) \
+ SYSLOG_IF(FATAL, !(condition)) << "Assert failed: " #condition ". "
+
+// A container for a string pointer which can be evaluated to a bool -
+// true iff the pointer is NULL.
+struct CheckOpString {
+ CheckOpString(std::string* str) : str_(str) { }
+ // No destructor: if str_ is non-NULL, we're about to LOG(FATAL),
+ // so there's no point in cleaning up str_.
+ operator bool() const { return str_ != NULL; }
+ std::string* str_;
+};
+
+// Build the error message string. This is separate from the "Impl"
+// function template because it is not performance critical and so can
+// be out of line, while the "Impl" code should be inline.
+template<class t1, class t2>
+std::string* MakeCheckOpString(const t1& v1, const t2& v2, const char* names) {
+ std::ostringstream ss;
+ ss << names << " (" << v1 << " vs. " << v2 << ")";
+ return new std::string(ss.str());
+}
+
+std::string* MakeCheckOpStringIntInt(int v1, int v2, const char* names);
+
+template<int, int>
+std::string* MakeCheckOpString(const int& v1, const int& v2, const char* names) {
+ return MakeCheckOpStringIntInt(v1, v2, names);
+}
+
+// Plus some debug-logging macros that get compiled to nothing for production
+//
+// DEBUG_MODE is for uses like
+// if (DEBUG_MODE) foo.CheckThatFoo();
+// instead of
+// #ifndef NDEBUG
+// foo.CheckThatFoo();
+// #endif
+
+#ifndef NDEBUG
+
+#define DLOG(severity) LOG(severity)
+#define DLOG_IF(severity, condition) LOG_IF(severity, condition)
+#define DLOG_ASSERT(condition) LOG_ASSERT(condition)
+
+// debug-only checking. not executed in NDEBUG mode.
+enum { DEBUG_MODE = 1 };
+#define DCHECK(condition) \
+ LOG_IF(FATAL, !(condition)) << "Check failed: " #condition ". "
+
+// Helper functions for DCHECK_OP macro.
+// The (int, int) specialization works around the issue that the compiler
+// will not instantiate the template version of the function on values of
+// unnamed enum type - see comment below.
+#define DEFINE_DCHECK_OP_IMPL(name, op) \
+ template <class t1, class t2> \
+ inline std::string* Check##name##Impl(const t1& v1, const t2& v2, \
+ const char* names) { \
+ if (v1 op v2) return NULL; \
+ else return MakeCheckOpString(v1, v2, names); \
+ } \
+ inline std::string* Check##name##Impl(int v1, int v2, const char* names) { \
+ if (v1 op v2) return NULL; \
+ else return MakeCheckOpString(v1, v2, names); \
+ }
+DEFINE_DCHECK_OP_IMPL(EQ, ==)
+DEFINE_DCHECK_OP_IMPL(NE, !=)
+DEFINE_DCHECK_OP_IMPL(LE, <=)
+DEFINE_DCHECK_OP_IMPL(LT, < )
+DEFINE_DCHECK_OP_IMPL(GE, >=)
+DEFINE_DCHECK_OP_IMPL(GT, > )
+#undef DEFINE_DCHECK_OP_IMPL
+
+// Helper macro for binary operators.
+// Don't use this macro directly in your code, use CHECK_EQ et al below.
+#define DCHECK_OP(name, op, val1, val2) \
+ while (logging::CheckOpString _result = \
+ logging::Check##name##Impl((val1), (val2), #val1 " " #op " " #val2)) \
+ logging::LogMessage(__FILE__, __LINE__, _result).stream()
+
+// Equality/Inequality checks - compare two values, and log a LOG_FATAL message
+// including the two values when the result is not as expected. The values
+// must have operator<<(ostream, ...) defined.
+//
+// You may append to the error message like so:
+// CHECK_NE(1, 2) << ": The world must be ending!";
+//
+// We are very careful to ensure that each argument is evaluated exactly
+// once, and that anything which is legal to pass as a function argument is
+// legal here. In particular, the arguments may be temporary expressions
+// which will end up being destroyed at the end of the apparent statement,
+// for example:
+// CHECK_EQ(string("abc")[1], 'b');
+//
+// WARNING: These don't compile correctly if one of the arguments is a pointer
+// and the other is NULL. To work around this, simply static_cast NULL to the
+// type of the desired pointer.
+
+#define DCHECK_EQ(val1, val2) DCHECK_OP(EQ, ==, val1, val2)
+#define DCHECK_NE(val1, val2) DCHECK_OP(NE, !=, val1, val2)
+#define DCHECK_LE(val1, val2) DCHECK_OP(LE, <=, val1, val2)
+#define DCHECK_LT(val1, val2) DCHECK_OP(LT, < , val1, val2)
+#define DCHECK_GE(val1, val2) DCHECK_OP(GE, >=, val1, val2)
+#define DCHECK_GT(val1, val2) DCHECK_OP(GT, > , val1, val2)
+
+// Helper functions for string comparisons.
+// To avoid bloat, the definitions are in logging.cc.
+#define DECLARE_DCHECK_STROP_IMPL(func, expected) \
+ std::string* Check##func##expected##Impl(const char* s1, \
+ const char* s2, \
+ const char* names);
+DECLARE_DCHECK_STROP_IMPL(strcmp, true)
+DECLARE_DCHECK_STROP_IMPL(strcmp, false)
+DECLARE_DCHECK_STROP_IMPL(_stricmp, true)
+DECLARE_DCHECK_STROP_IMPL(_stricmp, false)
+#undef DECLARE_DCHECK_STROP_IMPL
+
+// Helper macro for string comparisons.
+// Don't use this macro directly in your code, use CHECK_STREQ et al below.
+#define DCHECK_STROP(func, op, expected, s1, s2) \
+ while (CheckOpString _result = \
+ logging::Check##func##expected##Impl((s1), (s2), \
+ #s1 " " #op " " #s2)) \
+ LOG(FATAL) << *_result.str_
+
+// String (char*) equality/inequality checks.
+// CASE versions are case-insensitive.
+//
+// Note that "s1" and "s2" may be temporary strings which are destroyed
+// by the compiler at the end of the current "full expression"
+// (e.g. DCHECK_STREQ(Foo().c_str(), Bar().c_str())).
+
+#define DCHECK_STREQ(s1, s2) DCHECK_STROP(strcmp, ==, true, s1, s2)
+#define DCHECK_STRNE(s1, s2) DCHECK_STROP(strcmp, !=, false, s1, s2)
+#define DCHECK_STRCASEEQ(s1, s2) DCHECK_STROP(_stricmp, ==, true, s1, s2)
+#define DCHECK_STRCASENE(s1, s2) DCHECK_STROP(_stricmp, !=, false, s1, s2)
+
+#define DCHECK_INDEX(I,A) DCHECK(I < (sizeof(A)/sizeof(A[0])))
+#define DCHECK_BOUND(B,A) DCHECK(B <= (sizeof(A)/sizeof(A[0])))
+
+#else // NDEBUG
+
+#define DLOG(severity) \
+ true ? (void) 0 : logging::LogMessageVoidify() & LOG(severity)
+
+#define DLOG_IF(severity, condition) \
+ true ? (void) 0 : logging::LogMessageVoidify() & LOG(severity)
+
+#define DLOG_ASSERT(condition) \
+ true ? (void) 0 : LOG_ASSERT(condition)
+
+enum { DEBUG_MODE = 0 };
+
+// This macro can be followed by a sequence of stream parameters in
+// non-debug mode. The DCHECK and friends macros use this so that
+// the expanded expression DCHECK(foo) << "asdf" is still syntactically
+// valid, even though the expression will get optimized away.
+#define NDEBUG_EAT_STREAM_PARAMETERS \
+ logging::LogMessage(__FILE__, __LINE__).stream()
+
+#define DCHECK(condition) \
+ while (false) NDEBUG_EAT_STREAM_PARAMETERS
+
+#define DCHECK_EQ(val1, val2) \
+ while (false) NDEBUG_EAT_STREAM_PARAMETERS
+
+#define DCHECK_NE(val1, val2) \
+ while (false) NDEBUG_EAT_STREAM_PARAMETERS
+
+#define DCHECK_LE(val1, val2) \
+ while (false) NDEBUG_EAT_STREAM_PARAMETERS
+
+#define DCHECK_LT(val1, val2) \
+ while (false) NDEBUG_EAT_STREAM_PARAMETERS
+
+#define DCHECK_GE(val1, val2) \
+ while (false) NDEBUG_EAT_STREAM_PARAMETERS
+
+#define DCHECK_GT(val1, val2) \
+ while (false) NDEBUG_EAT_STREAM_PARAMETERS
+
+#define DCHECK_STREQ(str1, str2) \
+ while (false) NDEBUG_EAT_STREAM_PARAMETERS
+
+#define DCHECK_STRCASEEQ(str1, str2) \
+ while (false) NDEBUG_EAT_STREAM_PARAMETERS
+
+#define DCHECK_STRNE(str1, str2) \
+ while (false) NDEBUG_EAT_STREAM_PARAMETERS
+
+#define DCHECK_STRCASENE(str1, str2) \
+ while (false) NDEBUG_EAT_STREAM_PARAMETERS
+
+#endif // NDEBUG
+
+#define NOTREACHED() DCHECK(false)
+
+// Redefine the standard assert to use our nice log files
+#undef assert
+#define assert(x) DLOG_ASSERT(x)
+
+// This class more or less represents a particular log message. You
+// create an instance of LogMessage and then stream stuff to it.
+// When you finish streaming to it, ~LogMessage is called and the
+// full message gets streamed to the appropriate destination.
+//
+// You shouldn't actually use LogMessage's constructor to log things,
+// though. You should use the LOG() macro (and variants thereof)
+// above.
+class LogMessage {
+ public:
+ LogMessage(const char* file, int line, LogSeverity severity, int ctr);
+
+ // Two special constructors that generate reduced amounts of code at
+ // LOG call sites for common cases.
+ //
+ // Used for LOG(INFO): Implied are:
+ // severity = LOG_INFO, ctr = 0
+ //
+ // Using this constructor instead of the more complex constructor above
+ // saves a couple of bytes per call site.
+ LogMessage(const char* file, int line);
+
+ // Used for LOG(severity) where severity != INFO. Implied
+ // are: ctr = 0
+ //
+ // Using this constructor instead of the more complex constructor above
+ // saves a couple of bytes per call site.
+ LogMessage(const char* file, int line, LogSeverity severity);
+
+ // A special constructor used for check failures.
+ // Implied severity = LOG_FATAL
+ LogMessage(const char* file, int line, const CheckOpString& result);
+
+ ~LogMessage();
+
+ std::ostream& stream() { return stream_; }
+
+ private:
+ void Init(const char* file, int line);
+
+ LogSeverity severity_;
+ std::ostringstream stream_;
+ int message_start_; // offset of the start of the message (past prefix info).
+
+ DISALLOW_EVIL_CONSTRUCTORS(LogMessage);
+};
+
+// A non-macro interface to the log facility; (useful
+// when the logging level is not a compile-time constant).
+inline void LogAtLevel(int const log_level, std::string const &msg) {
+ LogMessage(__FILE__, __LINE__, log_level).stream() << msg;
+}
+
+// This class is used to explicitly ignore values in the conditional
+// logging macros. This avoids compiler warnings like "value computed
+// is not used" and "statement has no effect".
+class LogMessageVoidify {
+ public:
+ LogMessageVoidify() { }
+ // This has to be an operator with a precedence lower than << but
+ // higher than ?:
+ void operator&(std::ostream&) { }
+};
+
+// Closes the log file explicitly if open.
+// NOTE: Since the log file is opened as necessary by the action of logging
+// statements, there's no guarantee that it will stay closed
+// after this call.
+void CloseLogFile();
+
+} // namespace Logging
+
+// These functions are provided as a convenience for logging, which is where we
+// use streams (it is against Google style to use streams in other places). It
+// is designed to allow you to emit non-ASCII Unicode strings to the log file,
+// which is normally ASCII. It is relatively slow, so try not to use it for
+// common cases. Non-ASCII characters will be converted to UTF-8 by these operators.
+std::ostream& operator<<(std::ostream& out, const wchar_t* wstr);
+inline std::ostream& operator<<(std::ostream& out, const std::wstring& wstr) {
+ return out << wstr.c_str();
+}
+
+#endif // BASE_LOGGING_H__