From 4963c8a9d57501b5ffb0fe52fbfe60cd71b3b916 Mon Sep 17 00:00:00 2001 From: "thomasvl@gmail.com" Date: Mon, 21 Jul 2008 14:49:00 +0000 Subject: helps if I add the files before doing the commit --- Foundation/GTMLogger.h | 461 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 461 insertions(+) create mode 100644 Foundation/GTMLogger.h (limited to 'Foundation/GTMLogger.h') diff --git a/Foundation/GTMLogger.h b/Foundation/GTMLogger.h new file mode 100644 index 0000000..0565462 --- /dev/null +++ b/Foundation/GTMLogger.h @@ -0,0 +1,461 @@ +// +// GTMLogger.h +// +// Copyright 2007-2008 Google Inc. +// +// Licensed under the Apache License, Version 2.0 (the "License"); you may not +// use this file except in compliance with the License. You may obtain a copy +// of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT +// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the +// License for the specific language governing permissions and limitations under +// the License. +// + +// Key Abstractions +// ---------------- +// +// This file declares multiple classes and protocols that are used by the +// GTMLogger logging system. The 4 main abstractions used in this file are the +// following: +// +// * logger (GTMLogger) - The main logging class that users interact with. It +// has methods for logging at different levels and uses a log writer, a log +// formatter, and a log filter to get the job done. +// +// * log writer (GTMLogWriter) - Writes a given string to some log file, where +// a "log file" can be a physical file on disk, a POST over HTTP to some URL, +// or even some in-memory structure (e.g., a ring buffer). +// +// * log formatter (GTMLogFormatter) - Given a format string and arguments as +// a va_list, returns a single formatted NSString. A "formatted string" could +// be a string with the date prepended, a string with values in a CSV format, +// or even a string of XML. +// +// * log filter (GTMLogFilter) - Given a formatted log message as an NSString +// and the level at which the message is to be logged, this class will decide +// whether the given message should be logged or not. This is a flexible way +// to filter out messages logged at a certain level, messages that contain +// certain text, or filter nothing out at all. This gives the caller the +// flexibility to dynamically enable debug logging in Release builds. +// +// A class diagram showing the relationship between these key abstractions can +// be found at: http://www.corp.google.com/eng/designdocs/maceng/GTMLogger.png +// +// This file also declares some classes to handle the common log writer, log +// formatter, and log filter cases. Callers can also create their own writers, +// formatters, and filters and they can even build them on top of the ones +// declared here. Keep in mind that your custom writer/formatter/filter may be +// called from multiple threads, so it must be thread-safe. + +#import + +// Predeclaration of used protocols that are declared later in this file. +@protocol GTMLogWriter, GTMLogFormatter, GTMLogFilter; + +#if MAC_OS_X_VERSION_MIN_REQUIRED >= 1050 +#define CHECK_FORMAT_NSSTRING(a, b) __attribute__((format(__NSString__, a, b))) +#else +#define CHECK_FORMAT_NSSTRING(a, b) +#endif + +// GTMLogger +// +// GTMLogger is the primary user-facing class for an object-oriented logging +// system. It is built on the concept of log formatters (GTMLogFormatter), log +// writers (GTMLogWriter), and log filters (GTMLogFilter). When a message is +// sent to a GTMLogger to log a message, the message is formatted using the log +// formatter, then the log filter is consulted to see if the message should be +// logged, and if so, the message is sent to the log writer to be written out. +// +// GTMLogger is intended to be a flexible and thread-safe logging solution. Its +// flexibility comes from the fact that GTMLogger instances can be customized +// with user defined formatters, filters, and writers. And these writers, +// filters, and formatters can be combined, stacked, and customized in arbitrary +// ways to suit the needs at hand. For example, multiple writers can be used at +// the same time, and a GTMLogger instance can even be used as another +// GTMLogger's writer. This allows for arbitrarily deep logging trees. +// +// A standard GTMLogger uses a writer that sends messages to standard out, a +// formatter that smacks a timestamp and a few other bits of interesting +// information on the message, and a filter that filters out debug messages from +// release builds. Using the standard log settings, a log message will look like +// the following: +// +// 2007-12-30 10:29:24.177 myapp[4588/0xa07d0f60] [lvl=1] foo= +// +// The output contains the date and time of the log message, the name of the +// process followed by its process ID/thread ID, the log level at which the +// message was logged (in the previous example the level was 1: +// kGTMLoggerLevelDebug), and finally, the user-specified log message itself (in +// this case, the log message was @"foo=%@", foo). +// +// Multiple instances of GTMLogger can be created, each configured their own +// way. Though GTMLogger is not a singleton (in the GoF sense), it does provide +// access to a shared (i.e., globally accessible) GTMLogger instance. This makes +// it convenient for all code in a process to use the same GTMLogger instance. +// The shared GTMLogger instance can also be configured in an arbitrary, and +// these configuration changes will affect all code that logs through the shared +// instance. + +// +// Log Levels +// ---------- +// GTMLogger has 3 different log levels: Debug, Info, and Error. GTMLogger +// doesn't take any special action based on the log level; it simply forwards +// this information on to formatters, filters, and writers, each of which may +// optionally take action based on the level. Since log level filtering is +// performed at runtime, log messages are typically not filtered out at compile +// time. The exception to this rule is that calls to the GTMLoggerDebug() macro +// *ARE* filtered out of non-DEBUG builds. This is to be backwards compatible +// with behavior that many developers are currently used to. Note that this +// means that GTMLoggerDebug(@"hi") will be compiled out of Release builds, but +// [[GTMLogger sharedLogger] logDebug:@"hi"] will NOT be compiled out. +// +// Standard loggers are created with the GTMLogLevelFilter log filter, which +// filters out certain log messages based on log level, and some other settings. +// +// In addition to the -logDebug:, -logInfo:, and -logError: methods defined on +// GTMLogger itself, there are also C macros that make usage of the shared +// GTMLogger instance very convenient. These macros are: +// +// GTMLoggerDebug(...) +// GTMLoggerInfo(...) +// GTMLoggerError(...) +// +// Again, a notable feature of these macros is that GTMLogDebug() calls *will be +// compiled out of non-DEBUG builds*. +// +// Standard Loggers +// ---------------- +// GTMLogger has the concept of "standard loggers". A standard logger is simply +// a logger that is pre-configured with some standard/common writer, formatter, +// and filter combination. Standard loggers are created using the creation +// methods beginning with "standard". The alternative to a standard logger is a +// regular logger, which will send messages to stdout, with no special +// formatting, and no filtering. +// +// How do I use GTMLogger? +// ---------------------- +// The typical way you will want to use GTMLogger is to simply use the +// GTMLogger*() macros for logging from code. That way we can easily make +// changes to the GTMLogger class and simply update the macros accordingly. Only +// your application startup code (perhaps, somewhere in main()) should use the +// GTMLogger class directly in order to configure the shared logger, which all +// of the code using the macros will be using. Again, this is just the typical +// situation. +// +// To be complete, there are cases where you may want to use GTMLogger directly, +// or even create separate GTMLogger instances for some reason. That's fine, +// too. +// +// Examples +// -------- +// The following show some common GTMLogger use cases. +// +// 1. You want to log something as simply as possible. Also, this call will only +// appear in debug builds. In non-DEBUG builds it will be completely removed. +// +// GTMLoggerDebug(@"foo = %@", foo); +// +// 2. The previous example is similar to the following. The major difference is +// that the previous call (example 1) will be compiled out of Release builds +// but this statement will not be compiled out. +// +// [[GTMLogger sharedLogger] logDebug:@"foo = %@", foo]; +// +// 3. Send all logging output from the shared logger to a file. We do this by +// creating an NSFileHandle for writing associated with a file, and setting +// that file handle as the logger's writer. +// +// NSFileHandle *f = [NSFileHandle fileHandleForWritingAtPath:@"/tmp/f.log" +// create:YES]; +// [[GTMLogger sharedLogger] setWriter:f]; +// GTMLoggerError(@"hi"); // This will be sent to /tmp/f.log +// +// 4. Create a new GTMLogger that will log to a file. This example differs from +// the previous one because here we create a new GTMLogger that is different +// from the shared logger. +// +// GTMLogger *logger = [GTMLogger standardLoggerWithPath:@"/tmp/temp.log"]; +// [logger logInfo:@"hi temp log file"]; +// +// 5. Create a logger that writes to stdout and does NOT do any formatting to +// the log message. This might be useful, for example, when writing a help +// screen for a command-line tool to standard output. +// +// GTMLogger *logger = [GTMLogger logger]; +// [logger logInfo:@"%@ version 0.1 usage", progName]; +// +// 6. Send log output to stdout AND to a log file. The trick here is that +// NSArrays function as composite log writers, which means when an array is +// set as the log writer, it forwards all logging messages to all of its +// contained GTMLogWriters. +// +// // Create array of GTMLogWriters +// NSArray *writers = [NSArray arrayWithObjects: +// [NSFileHandle fileHandleForWritingAtPath:@"/tmp/f.log" create:YES], +// [NSFileHandle fileHandleWithStandardOutput], nil]; +// +// GTMLogger *logger = [GTMLogger standardLogger]; +// [logger setWriter:writers]; +// [logger logInfo:@"hi"]; // Output goes to stdout and /tmp/f.log +// +// For futher details on log writers, formatters, and filters, see the +// documentation below. +// +// NOTE: GTMLogger is application level logging. By default it does nothing +// with _GTMDevLog/_GTMDevAssert (see GTMDefines.h). An application can choose +// to bridge _GTMDevLog/_GTMDevAssert to GTMLogger by providing macro +// definitions in its prefix header (see GTMDefines.h for how one would do +// that). +// +@interface GTMLogger : NSObject { + @private + id writer_; + id formatter_; + id filter_; +} + +// +// Accessors for the shared logger instance +// + +// Returns a shared/global standard GTMLogger instance. Callers should typically +// use this method to get a GTMLogger instance, unless they explicitly want +// their own instance to configure for their own needs. This is the only method +// that returns a shared instance; all the rest return new GTMLogger instances. ++ (id)sharedLogger; + +// Sets the shared logger instance to |logger|. Future calls to +sharedLogger +// will return |logger| instead. ++ (void)setSharedLogger:(GTMLogger *)logger; + +// +// Creation methods +// + +// Returns a new autoreleased GTMLogger instance that will log to stdout, using +// the GTMLogStandardFormatter, and the GTMLogLevelFilter filter. ++ (id)standardLogger; + +// Same as +standardLogger, but logs to stderr. ++ (id)standardLoggerWithStderr; + +// Returns a new standard GTMLogger instance with a log writer that will +// write to the file at |path|, and will use the GTMLogStandardFormatter and +// GTMLogLevelFilter classes. If |path| does not exist, it will be created. ++ (id)standardLoggerWithPath:(NSString *)path; + +// Returns an autoreleased GTMLogger instance that will use the specified +// |writer|, |formatter|, and |filter|. ++ (id)loggerWithWriter:(id)writer + formatter:(id)formatter + filter:(id)filter; + +// Returns an autoreleased GTMLogger instance that logs to stdout, with the +// basic formatter, and no filter. The returned logger differs from the logger +// returned by +standardLogger because this one does not do any filtering and +// does not do any special log formatting; this is the difference between a +// "regular" logger and a "standard" logger. ++ (id)logger; + +// Designated initializer. This method returns a GTMLogger initialized with the +// specified |writer|, |formatter|, and |filter|. See the setter methods below +// for what values will be used if nil is passed for a parameter. +- (id)initWithWriter:(id)writer + formatter:(id)formatter + filter:(id)filter; + +// +// Logging methods +// + +// Logs a message at the debug level (kGTMLoggerLevelDebug). +- (void)logDebug:(NSString *)fmt, ... CHECK_FORMAT_NSSTRING(1, 2); +// Logs a message at the info level (kGTMLoggerLevelInfo). +- (void)logInfo:(NSString *)fmt, ... CHECK_FORMAT_NSSTRING(1, 2); +// Logs a message at the error level (kGTMLoggerLevelError). +- (void)logError:(NSString *)fmt, ... CHECK_FORMAT_NSSTRING(1, 2); +// Logs a message at the assert level (kGTMLoggerLevelAssert). +- (void)logAssert:(NSString *)fmt, ... CHECK_FORMAT_NSSTRING(1, 2); + + +// +// Accessors +// + +// Accessor methods for the log writer. If the log writer is set to nil, +// [NSFileHandle fileHandleWithStandardOutput] is used. +- (id)writer; +- (void)setWriter:(id)writer; + +// Accessor methods for the log formatter. If the log formatter is set to nil, +// GTMLogBasicFormatter is used. This formatter will format log messages in a +// plain printf style. +- (id)formatter; +- (void)setFormatter:(id)formatter; + +// Accessor methods for the log filter. If the log filter is set to nil, +// GTMLogNoFilter is used, which allows all log messages through. +- (id)filter; +- (void)setFilter:(id)filter; + +@end // GTMLogger + + +// Helper functions that are used by the convenience GTMLogger*() macros that +// enable the logging of function names. +@interface GTMLogger (GTMLoggerMacroHelpers) +- (void)logFuncDebug:(const char *)func msg:(NSString *)fmt, ... + CHECK_FORMAT_NSSTRING(2, 3); +- (void)logFuncInfo:(const char *)func msg:(NSString *)fmt, ... + CHECK_FORMAT_NSSTRING(2, 3); +- (void)logFuncError:(const char *)func msg:(NSString *)fmt, ... + CHECK_FORMAT_NSSTRING(2, 3); +- (void)logFuncAssert:(const char *)func msg:(NSString *)fmt, ... + CHECK_FORMAT_NSSTRING(2, 3); +@end // GTMLoggerMacroHelpers + + +// Convenience macros that log to the shared GTMLogger instance. These macros +// are how users should typically log to GTMLogger. Notice that GTMLoggerDebug() +// calls will be compiled out of non-Debug builds. +#define GTMLoggerDebug(...) \ + [[GTMLogger sharedLogger] logFuncDebug:__func__ msg:__VA_ARGS__] +#define GTMLoggerInfo(...) \ + [[GTMLogger sharedLogger] logFuncInfo:__func__ msg:__VA_ARGS__] +#define GTMLoggerError(...) \ + [[GTMLogger sharedLogger] logFuncError:__func__ msg:__VA_ARGS__] +#define GTMLoggerAssert(...) \ + [[GTMLogger sharedLogger] logFuncAssert:__func__ msg:__VA_ARGS__] + +// If we're not in a debug build, remove the GTMLoggerDebug statements. This +// makes calls to GTMLoggerDebug "compile out" of Release builds +#ifndef DEBUG +#undef GTMLoggerDebug +#define GTMLoggerDebug(...) do {} while(0) +#endif + +// Log levels. +typedef enum { + kGTMLoggerLevelUnknown, + kGTMLoggerLevelDebug, + kGTMLoggerLevelInfo, + kGTMLoggerLevelError, + kGTMLoggerLevelAssert, +} GTMLoggerLevel; + + +// +// Log Writers +// + +// Protocol to be implemented by a GTMLogWriter instance. +@protocol GTMLogWriter +// Writes the given log message to where the log writer is configured to write. +- (void)logMessage:(NSString *)msg level:(GTMLoggerLevel)level; +@end // GTMLogWriter + + +// Simple category on NSFileHandle that makes NSFileHandles valid log writers. +// This is convenient because something like, say, +fileHandleWithStandardError +// now becomes a valid log writer. Log messages are written to the file handle +// with a newline appended. +@interface NSFileHandle (GTMFileHandleLogWriter) +// Opens the file at |path| in append mode, and creates the file with |mode| +// if it didn't previously exist. ++ (id)fileHandleForLoggingAtPath:(NSString *)path mode:(mode_t)mode; +@end // NSFileHandle + + +// This category makes NSArray a GTMLogWriter that can be composed of other +// GTMLogWriters. This is the classic Composite GoF design pattern. When the +// GTMLogWriter -logMessage:level: message is sent to the array, the array +// forwards the message to all of its elements that implement the GTMLogWriter +// protocol. +// +// This is useful in situations where you would like to send log output to +// multiple log writers at the same time. Simply create an NSArray of the log +// writers you wish to use, then set the array as the "writer" for your +// GTMLogger instance. +@interface NSArray (GTMArrayCompositeLogWriter) +@end // GTMArrayCompositeLogWriter + + +// This category adapts the GTMLogger interface so that it can be used as a log +// writer; it's an "adapter" in the GoF Adapter pattern sense. +// +// This is useful when you want to configure a logger to log to a specific +// writer with a specific formatter and/or filter. But you want to also compose +// that with a different log writer that may have its own formatter and/or +// filter. +@interface GTMLogger (GTMLoggerLogWriter) +@end // GTMLoggerLogWriter + + +// +// Log Formatters +// + +// Protocol to be implemented by a GTMLogFormatter instance. +@protocol GTMLogFormatter +// Returns a formatted string using the format specified in |fmt| and the va +// args specified in |args|. +- (NSString *)stringForFunc:(NSString *)func + withFormat:(NSString *)fmt + valist:(va_list)args + level:(GTMLoggerLevel)level; +@end // GTMLogFormatter + + +// A basic log formatter that formats a string the same way that NSLog (or +// printf) would. It does not do anything fancy, nor does it add any data of its +// own. +@interface GTMLogBasicFormatter : NSObject +@end // GTMLogBasicFormatter + + +// A log formatter that formats the log string like the basic formatter, but +// also prepends a timestamp and some basic process info to the message, as +// shown in the following sample output. +// 2007-12-30 10:29:24.177 myapp[4588/0xa07d0f60] [lvl=1] log mesage here +@interface GTMLogStandardFormatter : GTMLogBasicFormatter { + @private + NSDateFormatter *dateFormatter_; // yyyy-MM-dd HH:mm:ss.SSS + NSString *pname_; + pid_t pid_; +} +@end // GTMLogStandardFormatter + + +// +// Log Filters +// + +// Protocol to be imlemented by a GTMLogFilter instance. +@protocol GTMLogFilter +// Returns YES if |msg| at |level| should be filtered out; NO otherwise. +- (BOOL)filterAllowsMessage:(NSString *)msg level:(GTMLoggerLevel)level; +@end // GTMLogFilter + + +// A log filter that filters messages at the kGTMLoggerLevelDebug level out of +// non-debug builds. Messages at the kGTMLoggerLevelInfo level are also filtered +// out of non-debug builds unless GTMVerboseLogging is set in the environment or +// the processes's defaults. Messages at the kGTMLoggerLevelError level are +// never filtered. +@interface GTMLogLevelFilter : NSObject +@end // GTMLogLevelFilter + + +// A simple log filter that does NOT filter anything out; +// -filterAllowsMessage:level will always return YES. This can be a convenient +// way to enable debug-level logging in release builds (if you so desire). +@interface GTMLogNoFilter : NSObject +@end // GTMLogNoFilter + -- cgit v1.2.3