LCOV - code coverage report
Current view: directory - js/xpconnect/loader - mozJSLoaderUtils.cpp (source / functions) Found Hit Coverage
Test: app.info Lines: 57 55 96.5 %
Date: 2012-06-02 Functions: 4 4 100.0 %

       1                 : /* ***** BEGIN LICENSE BLOCK *****
       2                 :  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
       3                 :  *
       4                 :  * The contents of this file are subject to the Mozilla Public License Version
       5                 :  * 1.1 (the "License"); you may not use this file except in compliance with
       6                 :  * the License. You may obtain a copy of the License at
       7                 :  * http://www.mozilla.org/MPL/
       8                 :  *
       9                 :  * Software distributed under the License is distributed on an "AS IS" basis,
      10                 :  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
      11                 :  * for the specific language governing rights and limitations under the
      12                 :  * License.
      13                 :  *
      14                 :  * The Original Code is mozilla.org
      15                 :  *
      16                 :  * The Initial Developer of the Original Code is
      17                 :  * Mozilla Foundation.
      18                 :  * Portions created by the Initial Developer are Copyright (C) 2010-2011
      19                 :  * the Initial Developer. All Rights Reserved.
      20                 :  *
      21                 :  * Contributor(s):
      22                 :  *   Michael Wu <mwu@mozilla.com>
      23                 :  *
      24                 :  * Alternatively, the contents of this file may be used under the terms of
      25                 :  * either of the GNU General Public License Version 2 or later (the "GPL"),
      26                 :  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
      27                 :  * in which case the provisions of the GPL or the LGPL are applicable instead
      28                 :  * of those above. If you wish to allow use of your version of this file only
      29                 :  * under the terms of either the GPL or the LGPL, and not to allow others to
      30                 :  * use your version of this file under the terms of the MPL, indicate your
      31                 :  * decision by deleting the provisions above and replace them with the notice
      32                 :  * and other provisions required by the GPL or the LGPL. If you do not delete
      33                 :  * the provisions above, a recipient may use your version of this file under
      34                 :  * the terms of any one of the MPL, the GPL or the LGPL.
      35                 :  *
      36                 :  * ***** END LICENSE BLOCK ***** */
      37                 : 
      38                 : #include "nsAutoPtr.h"
      39                 : #include "nsScriptLoader.h"
      40                 : 
      41                 : #include "jsapi.h"
      42                 : #include "jsxdrapi.h"
      43                 : 
      44                 : #include "mozilla/scache/StartupCache.h"
      45                 : #include "mozilla/scache/StartupCacheUtils.h"
      46                 : 
      47                 : using namespace mozilla::scache;
      48                 : 
      49                 : static nsresult
      50             642 : ReadScriptFromStream(JSContext *cx, nsIObjectInputStream *stream,
      51                 :                      JSScript **script)
      52                 : {
      53             642 :     *script = nsnull;
      54                 : 
      55                 :     PRUint32 size;
      56             642 :     nsresult rv = stream->Read32(&size);
      57             642 :     NS_ENSURE_SUCCESS(rv, rv);
      58                 : 
      59                 :     char *data;
      60             642 :     rv = stream->ReadBytes(size, &data);
      61             642 :     NS_ENSURE_SUCCESS(rv, rv);
      62                 : 
      63             642 :     JSXDRState *xdr = JS_XDRNewMem(cx, JSXDR_DECODE);
      64             642 :     NS_ENSURE_TRUE(xdr, NS_ERROR_OUT_OF_MEMORY);
      65                 : 
      66             642 :     xdr->userdata = stream;
      67             642 :     JS_XDRMemSetData(xdr, data, size);
      68                 : 
      69             642 :     if (!JS_XDRScript(xdr, script)) {
      70               0 :         rv = NS_ERROR_FAILURE;
      71                 :     }
      72                 : 
      73                 :     // Update data in case ::JS_XDRScript called back into C++ code to
      74                 :     // read an XPCOM object.
      75                 :     //
      76                 :     // In that case, the serialization process must have flushed a run
      77                 :     // of counted bytes containing JS data at the point where the XPCOM
      78                 :     // object starts, after which an encoding C++ callback from the JS
      79                 :     // XDR code must have written the XPCOM object directly into the
      80                 :     // nsIObjectOutputStream.
      81                 :     //
      82                 :     // The deserialization process will XDR-decode counted bytes up to
      83                 :     // but not including the XPCOM object, then call back into C++ to
      84                 :     // read the object, then read more counted bytes and hand them off
      85                 :     // to the JSXDRState, so more JS data can be decoded.
      86                 :     //
      87                 :     // This interleaving of JS XDR data and XPCOM object data may occur
      88                 :     // several times beneath the call to ::JS_XDRScript, above.  At the
      89                 :     // end of the day, we need to free (via nsMemory) the data owned by
      90                 :     // the JSXDRState.  So we steal it back, nulling xdr's buffer so it
      91                 :     // doesn't get passed to ::JS_free by ::JS_XDRDestroy.
      92                 : 
      93                 :     uint32_t length;
      94             642 :     data = static_cast<char*>(JS_XDRMemGetData(xdr, &length));
      95             642 :     JS_XDRMemSetData(xdr, nsnull, 0);
      96             642 :     JS_XDRDestroy(xdr);
      97                 : 
      98                 :     // If data is null now, it must have been freed while deserializing an
      99                 :     // XPCOM object (e.g., a principal) beneath ::JS_XDRScript.
     100             642 :     nsMemory::Free(data);
     101                 : 
     102             642 :     return rv;
     103                 : }
     104                 : 
     105                 : static nsresult
     106            7375 : WriteScriptToStream(JSContext *cx, JSScript *script,
     107                 :                     nsIObjectOutputStream *stream)
     108                 : {
     109            7375 :     JSXDRState *xdr = JS_XDRNewMem(cx, JSXDR_ENCODE);
     110            7375 :     NS_ENSURE_TRUE(xdr, NS_ERROR_OUT_OF_MEMORY);
     111                 : 
     112            7375 :     xdr->userdata = stream;
     113            7375 :     nsresult rv = NS_OK;
     114                 : 
     115            7375 :     if (JS_XDRScript(xdr, &script)) {
     116                 :         // Get the encoded JSXDRState data and write it.  The JSXDRState owns
     117                 :         // this buffer memory and will free it beneath ::JS_XDRDestroy.
     118                 :         //
     119                 :         // If an XPCOM object needs to be written in the midst of the JS XDR
     120                 :         // encoding process, the C++ code called back from the JS engine (e.g.,
     121                 :         // nsEncodeJSPrincipals in caps/src/nsJSPrincipals.cpp) will flush data
     122                 :         // from the JSXDRState to aStream, then write the object, then return
     123                 :         // to JS XDR code with xdr reset so new JS data is encoded at the front
     124                 :         // of the xdr's data buffer.
     125                 :         //
     126                 :         // However many XPCOM objects are interleaved with JS XDR data in the
     127                 :         // stream, when control returns here from ::JS_XDRScript, we'll have
     128                 :         // one last buffer of data to write to aStream.
     129                 : 
     130                 :         uint32_t size;
     131                 :         const char* data = reinterpret_cast<const char*>
     132            7375 :                                            (JS_XDRMemGetData(xdr, &size));
     133            7375 :         NS_ASSERTION(data, "no decoded JSXDRState data!");
     134                 : 
     135            7375 :         rv = stream->Write32(size);
     136            7375 :         if (NS_SUCCEEDED(rv)) {
     137            7375 :             rv = stream->WriteBytes(data, size);
     138                 :         }
     139                 :     } else {
     140               0 :         rv = NS_ERROR_FAILURE; // likely to be a principals serialization error
     141                 :     }
     142                 : 
     143            7375 :     JS_XDRDestroy(xdr);
     144            7375 :     return rv;
     145                 : }
     146                 : 
     147                 : nsresult
     148            8100 : ReadCachedScript(StartupCache* cache, nsACString &uri, JSContext *cx, JSScript **script)
     149                 : {
     150                 :     nsresult rv;
     151                 : 
     152           16200 :     nsAutoArrayPtr<char> buf;
     153                 :     PRUint32 len;
     154            8100 :     rv = cache->GetBuffer(PromiseFlatCString(uri).get(), getter_Transfers(buf),
     155            8100 :                           &len);
     156            8100 :     if (NS_FAILED(rv)) {
     157            7458 :         return rv; // don't warn since NOT_AVAILABLE is an ok error
     158                 :     }
     159                 : 
     160            1284 :     nsCOMPtr<nsIObjectInputStream> ois;
     161             642 :     rv = NewObjectInputStreamFromBuffer(buf, len, getter_AddRefs(ois));
     162             642 :     NS_ENSURE_SUCCESS(rv, rv);
     163             642 :     buf.forget();
     164                 : 
     165             642 :     return ReadScriptFromStream(cx, ois, script);
     166                 : }
     167                 : 
     168                 : nsresult
     169            7375 : WriteCachedScript(StartupCache* cache, nsACString &uri, JSContext *cx, JSScript *script)
     170                 : {
     171                 :     nsresult rv;
     172                 : 
     173           14750 :     nsCOMPtr<nsIObjectOutputStream> oos;
     174           14750 :     nsCOMPtr<nsIStorageStream> storageStream;
     175            7375 :     rv = NewObjectOutputWrappedStorageStream(getter_AddRefs(oos),
     176            7375 :                                              getter_AddRefs(storageStream),
     177            7375 :                                              true);
     178            7375 :     NS_ENSURE_SUCCESS(rv, rv);
     179                 : 
     180            7375 :     rv = WriteScriptToStream(cx, script, oos);
     181            7375 :     oos->Close();
     182            7375 :     NS_ENSURE_SUCCESS(rv, rv);
     183                 : 
     184           14750 :     nsAutoArrayPtr<char> buf;
     185                 :     PRUint32 len;
     186            7375 :     rv = NewBufferFromStorageStream(storageStream, getter_Transfers(buf), &len);
     187            7375 :     NS_ENSURE_SUCCESS(rv, rv);
     188                 : 
     189            7375 :     rv = cache->PutBuffer(PromiseFlatCString(uri).get(), buf, len);
     190            7375 :     return rv;
     191                 : }

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