[rtp_rtcp] SSRCDatabase class cleaned (including all lint errors)

BUG=webrtc:5277
R=mflodman

Review URL: https://codereview.webrtc.org/1507313005

Cr-Commit-Position: refs/heads/master@{#11023}

webrtc/modules/rtp_rtcp/source/ssrc_database.cc

@@ -10,92 +10,51 @@
 
 #include "webrtc/modules/rtp_rtcp/source/ssrc_database.h"
 
-#include <assert.h>
-#include <stdlib.h>
-
+#include "webrtc/base/checks.h"
+#include "webrtc/system_wrappers/include/clock.h"
 #include "webrtc/system_wrappers/include/critical_section_wrapper.h"
 
-#ifdef _WIN32
-#include <windows.h>
-#include <MMSystem.h>  // timeGetTime
-
-// TODO(hellner): investigate if it is necessary to disable these warnings.
-#pragma warning(disable : 4311)
-#pragma warning(disable : 4312)
-#else
-#include <stdio.h>
-#include <string.h>
-#include <time.h>
-#include <sys/time.h>
-#endif
-
 namespace webrtc {
-SSRCDatabase* SSRCDatabase::StaticInstance(CountOperation count_operation) {
-  SSRCDatabase* impl = GetStaticInstance<SSRCDatabase>(count_operation);
-  return impl;
+namespace {
+uint64_t Seed() {
+  return Clock::GetRealTimeClock()->TimeInMicroseconds();
 }
+}  // namespace
 
 SSRCDatabase* SSRCDatabase::GetSSRCDatabase() {
-  return StaticInstance(kAddRef);
+  return GetStaticInstance<SSRCDatabase>(kAddRef);
 }
 
 void SSRCDatabase::ReturnSSRCDatabase() {
-  StaticInstance(kRelease);
+  GetStaticInstance<SSRCDatabase>(kRelease);
 }
 
 uint32_t SSRCDatabase::CreateSSRC() {
-  CriticalSectionScoped lock(_critSect);
+  CriticalSectionScoped lock(crit_.get());
 
-  uint32_t ssrc = GenerateRandom();
-
-  while (_ssrcMap.find(ssrc) != _ssrcMap.end()) {
-    ssrc = GenerateRandom();
+  while (true) {  // Try until get a new ssrc.
+    // 0 and 0xffffffff are invalid values for SSRC.
+    uint32_t ssrc = random_.Rand(1u, 0xfffffffe);
+    if (ssrcs_.insert(ssrc).second) {
+      return ssrc;
+    }
   }
-  _ssrcMap[ssrc] = 0;
-
-  return ssrc;
 }
 
-int32_t SSRCDatabase::RegisterSSRC(const uint32_t ssrc) {
-  CriticalSectionScoped lock(_critSect);
-  _ssrcMap[ssrc] = 0;
-  return 0;
+void SSRCDatabase::RegisterSSRC(uint32_t ssrc) {
+  CriticalSectionScoped lock(crit_.get());
+  ssrcs_.insert(ssrc);
 }
 
-int32_t SSRCDatabase::ReturnSSRC(const uint32_t ssrc) {
-  CriticalSectionScoped lock(_critSect);
-  _ssrcMap.erase(ssrc);
-  return 0;
+void SSRCDatabase::ReturnSSRC(uint32_t ssrc) {
+  CriticalSectionScoped lock(crit_.get());
+  ssrcs_.erase(ssrc);
 }
 
-SSRCDatabase::SSRCDatabase() {
-// we need to seed the random generator, otherwise we get 26500 each time,
-// hardly a random value :)
-#ifdef _WIN32
-  srand(timeGetTime());
-#else
-  struct timeval tv;
-  struct timezone tz;
-  gettimeofday(&tv, &tz);
-  srand(tv.tv_usec);
-#endif
-
-  _critSect = CriticalSectionWrapper::CreateCriticalSection();
-}
+SSRCDatabase::SSRCDatabase()
+    : crit_(CriticalSectionWrapper::CreateCriticalSection()), random_(Seed()) {}
 
 SSRCDatabase::~SSRCDatabase() {
-  _ssrcMap.clear();
-  delete _critSect;
 }
 
-uint32_t SSRCDatabase::GenerateRandom() {
-  uint32_t ssrc = 0;
-  do {
-    ssrc = rand();
-    ssrc = ssrc << 16;
-    ssrc += rand();
-  } while (ssrc == 0 || ssrc == 0xffffffff);
-
-  return ssrc;
-}
 }  // namespace webrtc

webrtc/modules/rtp_rtcp/source/ssrc_database.h

@@ -11,8 +11,10 @@
 #ifndef WEBRTC_MODULES_RTP_RTCP_SOURCE_SSRC_DATABASE_H_
 #define WEBRTC_MODULES_RTP_RTCP_SOURCE_SSRC_DATABASE_H_
 
-#include <map>
+#include <set>
 
+#include "webrtc/base/random.h"
+#include "webrtc/base/scoped_ptr.h"
 #include "webrtc/system_wrappers/include/static_instance.h"
 #include "webrtc/typedefs.h"
 
@@ -25,8 +27,8 @@ class SSRCDatabase {
   static void ReturnSSRCDatabase();
 
   uint32_t CreateSSRC();
-  int32_t RegisterSSRC(const uint32_t ssrc);
-  int32_t ReturnSSRC(const uint32_t ssrc);
+  void RegisterSSRC(uint32_t ssrc);
+  void ReturnSSRC(uint32_t ssrc);
 
  protected:
   SSRCDatabase();
@@ -39,13 +41,10 @@ class SSRCDatabase {
   // template class.
   friend SSRCDatabase* GetStaticInstance<SSRCDatabase>(
       CountOperation count_operation);
-  static SSRCDatabase* StaticInstance(CountOperation count_operation);
 
-  uint32_t GenerateRandom();
-
-  std::map<uint32_t, uint32_t> _ssrcMap;
-
-  CriticalSectionWrapper* _critSect;
+  rtc::scoped_ptr<CriticalSectionWrapper> crit_;
+  Random random_ GUARDED_BY(crit_);
+  std::set<uint32_t> ssrcs_ GUARDED_BY(crit_);
 };
 }  // namespace webrtc