startupcache/StartupCacheUtils.cpp
author Gregory Szorc <gps@mozilla.com>
Thu, 19 Feb 2015 10:58:41 -0800
changeset 245738 c97c977c92b97c9585011651b13a088f0cd4ed4f
parent 184354 ff0eb85179cd93b259ee76bfdac3a032809c360e
child 276135 91c69276782a255aaaff1e27c3fe339b63134472
permissions -rw-r--r--
Bug 1132771 - moz.build fixups to enable execution in no config mode Various moz.build files fail to execute when a build config is not present. Many of these are due to assuming certain CONFIG entries are present. This patch attempts to fix that and enable every moz.build to be read without a build config.

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsCOMPtr.h"
#include "nsIInputStream.h"
#include "nsIStringStream.h"
#include "nsNetUtil.h"
#include "nsIJARURI.h"
#include "nsIResProtocolHandler.h"
#include "nsIChromeRegistry.h"
#include "nsAutoPtr.h"
#include "StartupCacheUtils.h"
#include "mozilla/scache/StartupCache.h"
#include "mozilla/Omnijar.h"

namespace mozilla {
namespace scache {

NS_EXPORT nsresult
NewObjectInputStreamFromBuffer(char* buffer, uint32_t len, 
                               nsIObjectInputStream** stream)
{
  nsCOMPtr<nsIStringInputStream> stringStream
    = do_CreateInstance("@mozilla.org/io/string-input-stream;1");
  nsCOMPtr<nsIObjectInputStream> objectInput 
    = do_CreateInstance("@mozilla.org/binaryinputstream;1");
  
  stringStream->AdoptData(buffer, len);
  objectInput->SetInputStream(stringStream);
  
  objectInput.forget(stream);
  return NS_OK;
}

NS_EXPORT nsresult
NewObjectOutputWrappedStorageStream(nsIObjectOutputStream **wrapperStream,
                                    nsIStorageStream** stream,
                                    bool wantDebugStream)
{
  nsCOMPtr<nsIStorageStream> storageStream;

  nsresult rv = NS_NewStorageStream(256, UINT32_MAX, getter_AddRefs(storageStream));
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsIObjectOutputStream> objectOutput
    = do_CreateInstance("@mozilla.org/binaryoutputstream;1");
  nsCOMPtr<nsIOutputStream> outputStream
    = do_QueryInterface(storageStream);
  
  objectOutput->SetOutputStream(outputStream);
  
#ifdef DEBUG
  if (wantDebugStream) {
    // Wrap in debug stream to detect unsupported writes of 
    // multiply-referenced non-singleton objects
    StartupCache* sc = StartupCache::GetSingleton();
    NS_ENSURE_TRUE(sc, NS_ERROR_UNEXPECTED);
    nsCOMPtr<nsIObjectOutputStream> debugStream;
    sc->GetDebugObjectOutputStream(objectOutput, getter_AddRefs(debugStream));
    debugStream.forget(wrapperStream);
  } else {
    objectOutput.forget(wrapperStream);
  }
#else
  objectOutput.forget(wrapperStream);
#endif
  
  storageStream.forget(stream);
  return NS_OK;
}

NS_EXPORT nsresult
NewBufferFromStorageStream(nsIStorageStream *storageStream, 
                           char** buffer, uint32_t* len) 
{
  nsresult rv;
  nsCOMPtr<nsIInputStream> inputStream;
  rv = storageStream->NewInputStream(0, getter_AddRefs(inputStream));
  NS_ENSURE_SUCCESS(rv, rv);
  
  uint64_t avail64;
  rv = inputStream->Available(&avail64);
  NS_ENSURE_SUCCESS(rv, rv);
  NS_ENSURE_TRUE(avail64 <= UINT32_MAX, NS_ERROR_FILE_TOO_BIG);

  uint32_t avail = (uint32_t)avail64;
  nsAutoArrayPtr<char> temp (new char[avail]);
  uint32_t read;
  rv = inputStream->Read(temp, avail, &read);
  if (NS_SUCCEEDED(rv) && avail != read)
    rv = NS_ERROR_UNEXPECTED;
  
  if (NS_FAILED(rv)) {
    return rv;
  }
  
  *len = avail;
  *buffer = temp.forget();
  return NS_OK;
}

static const char baseName[2][5] = { "gre/", "app/" };

static inline bool
canonicalizeBase(nsAutoCString &spec,
                 nsACString &out)
{
    nsAutoCString greBase, appBase;
    nsresult rv = mozilla::Omnijar::GetURIString(mozilla::Omnijar::GRE, greBase);
    if (NS_FAILED(rv) || !greBase.Length())
        return false;

    rv = mozilla::Omnijar::GetURIString(mozilla::Omnijar::APP, appBase);
    if (NS_FAILED(rv))
        return false;

    bool underGre = !greBase.Compare(spec.get(), false, greBase.Length());
    bool underApp = appBase.Length() &&
                    !appBase.Compare(spec.get(), false, appBase.Length());

    if (!underGre && !underApp)
        return false;

    /**
     * At this point, if both underGre and underApp are true, it can be one
     * of the two following cases:
     * - the GRE directory points to a subdirectory of the APP directory,
     *   meaning spec points under GRE.
     * - the APP directory points to a subdirectory of the GRE directory,
     *   meaning spec points under APP.
     * Checking the GRE and APP path length is enough to know in which case
     * we are.
     */
    if (underGre && underApp && greBase.Length() < appBase.Length())
        underGre = false;

    out.AppendLiteral("/resource/");
    out.Append(baseName[underGre ? mozilla::Omnijar::GRE : mozilla::Omnijar::APP]);
    out.Append(Substring(spec, underGre ? greBase.Length() : appBase.Length()));
    return true;
}

/**
 * PathifyURI transforms uris into useful zip paths
 * to make it easier to manipulate startup cache entries
 * using standard zip tools.
 * Transformations applied:
 *  * resource:// URIs are resolved to their corresponding file/jar URI to
 *    canonicalize resources URIs other than gre and app.
 *  * Paths under GRE or APP directory have their base path replaced with
 *    resource/gre or resource/app to avoid depending on install location.
 *  * jar:file:///path/to/file.jar!/sub/path urls are replaced with
 *    /path/to/file.jar/sub/path
 *
 *  The result is appended to the string passed in. Adding a prefix before
 *  calling is recommended to avoid colliding with other cache users.
 *
 * For example, in the js loader (string is prefixed with jsloader by caller):
 *  resource://gre/modules/XPCOMUtils.jsm or
 *  file://$GRE_DIR/modules/XPCOMUtils.jsm or
 *  jar:file://$GRE_DIR/omni.jar!/modules/XPCOMUtils.jsm becomes
 *     jsloader/resource/gre/modules/XPCOMUtils.jsm
 *  file://$PROFILE_DIR/extensions/{uuid}/components/component.js becomes
 *     jsloader/$PROFILE_DIR/extensions/%7Buuid%7D/components/component.js
 *  jar:file://$PROFILE_DIR/extensions/some.xpi!/components/component.js becomes
 *     jsloader/$PROFILE_DIR/extensions/some.xpi/components/component.js
 */
NS_EXPORT nsresult
PathifyURI(nsIURI *in, nsACString &out)
{
    bool equals;
    nsresult rv;
    nsCOMPtr<nsIURI> uri = in;
    nsAutoCString spec;

    // Resolve resource:// URIs. At the end of this if/else block, we
    // have both spec and uri variables identifying the same URI.
    if (NS_SUCCEEDED(in->SchemeIs("resource", &equals)) && equals) {
        nsCOMPtr<nsIIOService> ioService = do_GetIOService(&rv);
        NS_ENSURE_SUCCESS(rv, rv);

        nsCOMPtr<nsIProtocolHandler> ph;
        rv = ioService->GetProtocolHandler("resource", getter_AddRefs(ph));
        NS_ENSURE_SUCCESS(rv, rv);

        nsCOMPtr<nsIResProtocolHandler> irph(do_QueryInterface(ph, &rv));
        NS_ENSURE_SUCCESS(rv, rv);

        rv = irph->ResolveURI(in, spec);
        NS_ENSURE_SUCCESS(rv, rv);

        rv = ioService->NewURI(spec, nullptr, nullptr, getter_AddRefs(uri));
        NS_ENSURE_SUCCESS(rv, rv);
    } else {
        if (NS_SUCCEEDED(in->SchemeIs("chrome", &equals)) && equals) {
            nsCOMPtr<nsIChromeRegistry> chromeReg =
                mozilla::services::GetChromeRegistryService();
            if (!chromeReg)
                return NS_ERROR_UNEXPECTED;

            rv = chromeReg->ConvertChromeURL(in, getter_AddRefs(uri));
            NS_ENSURE_SUCCESS(rv, rv);
        }

        rv = uri->GetSpec(spec);
        NS_ENSURE_SUCCESS(rv, rv);
    }

    if (!canonicalizeBase(spec, out)) {
        if (NS_SUCCEEDED(uri->SchemeIs("file", &equals)) && equals) {
            nsCOMPtr<nsIFileURL> baseFileURL;
            baseFileURL = do_QueryInterface(uri, &rv);
            NS_ENSURE_SUCCESS(rv, rv);

            nsAutoCString path;
            rv = baseFileURL->GetPath(path);
            NS_ENSURE_SUCCESS(rv, rv);

            out.Append(path);
        } else if (NS_SUCCEEDED(uri->SchemeIs("jar", &equals)) && equals) {
            nsCOMPtr<nsIJARURI> jarURI = do_QueryInterface(uri, &rv);
            NS_ENSURE_SUCCESS(rv, rv);

            nsCOMPtr<nsIURI> jarFileURI;
            rv = jarURI->GetJARFile(getter_AddRefs(jarFileURI));
            NS_ENSURE_SUCCESS(rv, rv);

            rv = PathifyURI(jarFileURI, out);
            NS_ENSURE_SUCCESS(rv, rv);

            nsAutoCString path;
            rv = jarURI->GetJAREntry(path);
            NS_ENSURE_SUCCESS(rv, rv);
            out.Append('/');
            out.Append(path);
        } else { // Very unlikely
            nsAutoCString spec;
            rv = uri->GetSpec(spec);
            NS_ENSURE_SUCCESS(rv, rv);

            out.Append('/');
            out.Append(spec);
        }
    }
    return NS_OK;
}

}
}