Bug 1009500 - HTTP cache v2: respect OPEN_BYPASS_IF_BUSY, r=michal

netwerk/cache2/CacheEntry.cpp

@@ -264,6 +264,7 @@ void CacheEntry::AsyncOpen(nsICacheEntryOpenCallback* aCallback, uint32_t aFlags
     this, StateString(mState), aFlags, aCallback));
 
   bool readonly = aFlags & nsICacheStorage::OPEN_READONLY;
+  bool bypassIfBusy = aFlags & nsICacheStorage::OPEN_BYPASS_IF_BUSY;
   bool truncate = aFlags & nsICacheStorage::OPEN_TRUNCATE;
   bool priority = aFlags & nsICacheStorage::OPEN_PRIORITY;
   bool multithread = aFlags & nsICacheStorage::CHECK_MULTITHREADED;
@@ -275,7 +276,7 @@ void CacheEntry::AsyncOpen(nsICacheEntryOpenCallback* aCallback, uint32_t aFlags
 
   mozilla::MutexAutoLock lock(mLock);
 
-  RememberCallback(callback);
+  RememberCallback(callback, bypassIfBusy);
 
   // Load() opens the lock
   if (Load(truncate, priority)) {
@@ -491,12 +492,20 @@ void CacheEntry::TransferCallbacks(CacheEntry & aFromEntry)
   }
 }
 
-void CacheEntry::RememberCallback(Callback const& aCallback)
+void CacheEntry::RememberCallback(Callback & aCallback, bool aBypassIfBusy)
 {
-  LOG(("CacheEntry::RememberCallback [this=%p, cb=%p]", this, aCallback.mCallback.get()));
-
   mLock.AssertCurrentThreadOwns();
 
+  LOG(("CacheEntry::RememberCallback [this=%p, cb=%p, state=%s]",
+    this, aCallback.mCallback.get(), StateString(mState)));
+
+  if (aBypassIfBusy && (mState == WRITING || mState == REVALIDATING)) {
+    LOG(("  writing or revalidating, callback wants to bypass cache"));
+    aCallback.mNotWanted = true;
+    InvokeAvailableCallback(aCallback);
+    return;
+  }
+
   mCallbacks.AppendElement(aCallback);
 }
 

netwerk/cache2/CacheEntry.h

@@ -210,7 +210,7 @@ private:
   bool Load(bool aTruncate, bool aPriority);
   void OnLoaded();
 
-  void RememberCallback(Callback const & aCallback);
+  void RememberCallback(Callback & aCallback, bool aBypassIfBusy);
   void InvokeCallbacksLock();
   void InvokeCallbacks();
   bool InvokeCallbacks(bool aReadOnly);

netwerk/test/unit/head_cache2.js

@@ -43,6 +43,8 @@ const RECREATE =        1 << 10;
 const NOTWANTED =       1 << 11;
 // Tell the cache to wait for the entry to be completely written first
 const COMPLETE =        1 << 12;
+// Don't write meta/data and don't set valid in the callback, consumer will do it manually
+const DONTFILL =        1 << 13;
 
 var log_c2 = true;
 function LOG_C2(o, m)
@@ -179,6 +181,11 @@ OpenCallback.prototype =
         catch (ex) {}
       }
 
+      if (this.behavior & DONTFILL) {
+        do_check_false(this.behavior & WAITFORWRITE);
+        return;
+      }
+
       var self = this;
       do_execute_soon(function() { // emulate network latency
         entry.setMetaDataElement("meto", self.workingMetadata);

netwerk/test/unit/test_cache2-01e-basic-bypass-if-busy.js

@@ -0,0 +1,35 @@
+function run_test()
+{
+  do_get_profile();
+
+  if (!newCacheBackEndUsed()) {
+    do_check_true(true, "This test doesn't run when the old cache back end is used since the behavior is different");
+    return;
+  }
+
+  // Open for write, delay the actual write
+  asyncOpenCacheEntry("http://a/", "disk", Ci.nsICacheStorage.OPEN_NORMALLY, null,
+    new OpenCallback(NEW|DONTFILL, "a1m", "a1d", function(entry) {
+      var bypassed = false;
+
+      // Open and bypass
+      asyncOpenCacheEntry("http://a/", "disk", Ci.nsICacheStorage.OPEN_BYPASS_IF_BUSY, null,
+        new OpenCallback(NOTFOUND, "", "", function(entry) {
+          do_check_false(bypassed);
+          bypassed = true;
+        })
+      );
+
+      // do_execute_soon for two reasons:
+      // 1. we want finish_cache2_test call for sure after do_test_pending, but all the callbacks here
+      //    may invoke synchronously
+      // 2. precaution when the OPEN_BYPASS_IF_BUSY invocation become a post one day
+      do_execute_soon(function() {
+        do_check_true(bypassed);
+        finish_cache2_test();
+      });
+    })
+  );
+
+  do_test_pending();
+}

netwerk/test/unit/xpcshell.ini

@@ -24,6 +24,7 @@ support-files =
 [test_cache2-01b-basic-datasize.js]
 [test_cache2-01c-basic-hasmeta-only.js]
 [test_cache2-01d-basic-not-wanted.js]
+[test_cache2-01e-basic-bypass-if-busy.js]
 [test_cache2-02-open-non-existing.js]
 [test_cache2-03-oncacheentryavail-throws.js]
 [test_cache2-04-oncacheentryavail-throws2x.js]