Bug 1036394 - Add support for getting the zip entry from the jar channel, r=jduell

modules/libjar/nsIJARChannel.idl

@@ -6,8 +6,9 @@
 #include "nsIChannel.idl"
 
 interface nsIFile;
+interface nsIZipEntry;
 
-[scriptable, builtinclass, uuid(5a4f8df0-3bd9-45c2-9db9-67e74c3dd47d)]
+[scriptable, builtinclass, uuid(8cce289f-1671-452e-b9c3-3b7366ec8337)]
 interface nsIJARChannel : nsIChannel
 {
     /**
@@ -28,6 +29,12 @@ interface nsIJARChannel : nsIChannel
      */
     readonly attribute nsIFile jarFile;
 
+    /**
+     * Returns the zip entry if the file is synchronously accessible.
+     * This will work even without opening the channel.
+     */
+    readonly attribute nsIZipEntry zipEntry;
+
     /**
      * For child process, set this to make sure that a valid file descriptor of
      * JAR file is always provided when calling NSPRFileDesc().

modules/libjar/nsJARChannel.cpp

@@ -323,6 +323,9 @@ nsJARChannel::LookupFile()
 {
     LOG(("nsJARChannel::LookupFile [this=%x %s]\n", this, mSpec.get()));
 
+    if (mJarFile)
+        return NS_OK;
+
     nsresult rv;
     nsCOMPtr<nsIURI> uri;
 
@@ -889,6 +892,24 @@ nsJARChannel::GetJarFile(nsIFile **aFile)
     return NS_OK;
 }
 
+NS_IMETHODIMP
+nsJARChannel::GetZipEntry(nsIZipEntry **aZipEntry)
+{
+    nsresult rv = LookupFile();
+    if (NS_FAILED(rv))
+        return rv;
+
+    if (!mJarFile)
+        return NS_ERROR_NOT_AVAILABLE;
+
+    nsCOMPtr<nsIZipReader> reader;
+    rv = gJarHandler->JarCache()->GetZip(mJarFile, getter_AddRefs(reader));
+    if (NS_FAILED(rv))
+        return rv;
+
+    return reader->GetEntry(mJarEntry, aZipEntry);
+}
+
 NS_IMETHODIMP
 nsJARChannel::EnsureChildFd()
 {

modules/libjar/test/unit/test_jarchannel.js

@@ -87,6 +87,20 @@ add_test(testAsync);
 // Run same test again so we test the codepath for a zipcache hit
 add_test(testAsync);
 
+/**
+ * Basic test for nsIZipReader.
+ * This relies on the jar cache to succeed in child processes.
+ */
+function testZipEntry() {
+    var uri = jarBase + "/inner40.zip";
+    var chan = ios.newChannel(uri, null, null).QueryInterface(Ci.nsIJARChannel);
+    var entry = chan.zipEntry;
+    do_check_true(entry.CRC32 == 0x8b635486);
+    do_check_true(entry.realSize == 184);
+    run_next_test();
+}
+
+add_test(testZipEntry);
 
 // In e10s child processes we don't currently support 
 // 1) synchronously opening jar files on parent

netwerk/protocol/app/AppProtocolHandler.cpp

@@ -127,6 +127,11 @@ NS_IMETHODIMP DummyChannel::GetJarFile(nsIFile* *aFile)
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 
+NS_IMETHODIMP DummyChannel::GetZipEntry(nsIZipEntry* *aEntry)
+{
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
 NS_IMETHODIMP DummyChannel::EnsureChildFd()
 {
   return NS_ERROR_NOT_IMPLEMENTED;