Obj-C SDK Cleanup

This CL separates the files under sdk/objc into logical directories, replacing
the previous file layout under Framework/.

A long term goal is to have some system set up to generate the files under
sdk/objc/api (the PeerConnection API wrappers) from the C++ code. In the shorter
term the goal is to abstract out shared concepts from these classes in order to
make them as uniform as possible.

The separation into base/, components/, and helpers/ are to differentiate between
the base layer's common protocols, various utilities and the actual platform
specific components.

The old directory layout that resembled a framework's internal layout is not
necessary, since it is generated by the framework target when building it.

Bug: webrtc:9627
Change-Id: Ib084fd83f050ae980649ca99e841f4fb0580bd8f
Reviewed-on: https://webrtc-review.googlesource.com/94142
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Rasmus Brandt <brandtr@webrtc.org>
Reviewed-by: Henrik Andreassson <henrika@webrtc.org>
Commit-Queue: Anders Carlsson <andersc@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24493}
diff --git a/sdk/objc/api/peerconnection/RTCFileLogger.mm b/sdk/objc/api/peerconnection/RTCFileLogger.mm
new file mode 100644
index 0000000..3a7144a
--- /dev/null
+++ b/sdk/objc/api/peerconnection/RTCFileLogger.mm
@@ -0,0 +1,175 @@
+/*
+ *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#import "RTCFileLogger.h"
+
+#include <memory>
+
+#include "rtc_base/checks.h"
+#include "rtc_base/filerotatingstream.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/logsinks.h"
+
+NSString *const kDefaultLogDirName = @"webrtc_logs";
+NSUInteger const kDefaultMaxFileSize = 10 * 1024 * 1024; // 10MB.
+const char *kRTCFileLoggerRotatingLogPrefix = "rotating_log";
+
+@implementation RTCFileLogger {
+  BOOL _hasStarted;
+  NSString *_dirPath;
+  NSUInteger _maxFileSize;
+  std::unique_ptr<rtc::FileRotatingLogSink> _logSink;
+}
+
+@synthesize severity = _severity;
+@synthesize rotationType = _rotationType;
+@synthesize shouldDisableBuffering = _shouldDisableBuffering;
+
+- (instancetype)init {
+  NSArray *paths = NSSearchPathForDirectoriesInDomains(
+      NSDocumentDirectory, NSUserDomainMask, YES);
+  NSString *documentsDirPath = [paths firstObject];
+  NSString *defaultDirPath =
+      [documentsDirPath stringByAppendingPathComponent:kDefaultLogDirName];
+  return [self initWithDirPath:defaultDirPath
+                   maxFileSize:kDefaultMaxFileSize];
+}
+
+- (instancetype)initWithDirPath:(NSString *)dirPath
+                    maxFileSize:(NSUInteger)maxFileSize {
+  return [self initWithDirPath:dirPath
+                   maxFileSize:maxFileSize
+                  rotationType:RTCFileLoggerTypeCall];
+}
+
+- (instancetype)initWithDirPath:(NSString *)dirPath
+                    maxFileSize:(NSUInteger)maxFileSize
+                   rotationType:(RTCFileLoggerRotationType)rotationType {
+  NSParameterAssert(dirPath.length);
+  NSParameterAssert(maxFileSize);
+  if (self = [super init]) {
+    BOOL isDir = NO;
+    NSFileManager *fileManager = [NSFileManager defaultManager];
+    if ([fileManager fileExistsAtPath:dirPath isDirectory:&isDir]) {
+      if (!isDir) {
+        // Bail if something already exists there.
+        return nil;
+      }
+    } else {
+      if (![fileManager createDirectoryAtPath:dirPath
+                  withIntermediateDirectories:NO
+                                   attributes:nil
+                                        error:nil]) {
+        // Bail if we failed to create a directory.
+        return nil;
+      }
+    }
+    _dirPath = dirPath;
+    _maxFileSize = maxFileSize;
+    _severity = RTCFileLoggerSeverityInfo;
+  }
+  return self;
+}
+
+- (void)dealloc {
+  [self stop];
+}
+
+- (void)start {
+  if (_hasStarted) {
+    return;
+  }
+  switch (_rotationType) {
+    case RTCFileLoggerTypeApp:
+      _logSink.reset(
+          new rtc::FileRotatingLogSink(_dirPath.UTF8String,
+                                       kRTCFileLoggerRotatingLogPrefix,
+                                       _maxFileSize,
+                                       _maxFileSize / 10));
+      break;
+    case RTCFileLoggerTypeCall:
+      _logSink.reset(
+          new rtc::CallSessionFileRotatingLogSink(_dirPath.UTF8String,
+                                                  _maxFileSize));
+      break;
+  }
+  if (!_logSink->Init()) {
+    RTC_LOG(LS_ERROR) << "Failed to open log files at path: " << _dirPath.UTF8String;
+    _logSink.reset();
+    return;
+  }
+  if (_shouldDisableBuffering) {
+    _logSink->DisableBuffering();
+  }
+  rtc::LogMessage::LogThreads(true);
+  rtc::LogMessage::LogTimestamps(true);
+  rtc::LogMessage::AddLogToStream(_logSink.get(), [self rtcSeverity]);
+  _hasStarted = YES;
+}
+
+- (void)stop {
+  if (!_hasStarted) {
+    return;
+  }
+  RTC_DCHECK(_logSink);
+  rtc::LogMessage::RemoveLogToStream(_logSink.get());
+  _hasStarted = NO;
+  _logSink.reset();
+}
+
+- (nullable NSData *)logData {
+  if (_hasStarted) {
+    return nil;
+  }
+  NSMutableData* logData = [NSMutableData data];
+  std::unique_ptr<rtc::FileRotatingStream> stream;
+  switch(_rotationType) {
+    case RTCFileLoggerTypeApp:
+      stream.reset(
+          new rtc::FileRotatingStream(_dirPath.UTF8String,
+                                      kRTCFileLoggerRotatingLogPrefix));
+      break;
+    case RTCFileLoggerTypeCall:
+      stream.reset(new rtc::CallSessionFileRotatingStream(_dirPath.UTF8String));
+      break;
+  }
+  if (!stream->Open()) {
+    return logData;
+  }
+  size_t bufferSize = 0;
+  if (!stream->GetSize(&bufferSize) || bufferSize == 0) {
+    return logData;
+  }
+  size_t read = 0;
+  // Allocate memory using malloc so we can pass it direcly to NSData without
+  // copying.
+  std::unique_ptr<uint8_t[]> buffer(static_cast<uint8_t*>(malloc(bufferSize)));
+  stream->ReadAll(buffer.get(), bufferSize, &read, nullptr);
+  logData = [[NSMutableData alloc] initWithBytesNoCopy:buffer.release()
+                                                length:read];
+  return logData;
+}
+
+#pragma mark - Private
+
+- (rtc::LoggingSeverity)rtcSeverity {
+  switch (_severity) {
+    case RTCFileLoggerSeverityVerbose:
+      return rtc::LS_VERBOSE;
+    case RTCFileLoggerSeverityInfo:
+      return rtc::LS_INFO;
+    case RTCFileLoggerSeverityWarning:
+      return rtc::LS_WARNING;
+    case RTCFileLoggerSeverityError:
+      return rtc::LS_ERROR;
+  }
+}
+
+@end