Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 848 insertions, 0 deletions

diff --git a/modules/libjar/nsJAR.cpp b/modules/libjar/nsJAR.cpp
new file mode 100644
index 0000000000..28ff746d16
--- /dev/null
+++ b/modules/libjar/nsJAR.cpp
@@ -0,0 +1,848 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 <string.h>
+#include "nsJARInputStream.h"
+#include "nsJAR.h"
+#include "nsIFile.h"
+#include "nsIObserverService.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/Omnijar.h"
+#include "mozilla/Unused.h"
+
+#ifdef XP_UNIX
+#  include <sys/stat.h>
+#elif defined(XP_WIN)
+#  include <io.h>
+#endif
+
+using namespace mozilla;
+
+//----------------------------------------------
+// nsJAR constructor/destructor
+//----------------------------------------------
+
+// The following initialization makes a guess of 10 entries per jarfile.
+nsJAR::nsJAR()
+    : mZip(new nsZipArchive()),
+      mReleaseTime(PR_INTERVAL_NO_TIMEOUT),
+      mCache(nullptr),
+      mLock("nsJAR::mLock"),
+      mMtime(0),
+      mOpened(false),
+      mSkipArchiveClosing(false) {}
+
+nsJAR::~nsJAR() { Close(); }
+
+NS_IMPL_QUERY_INTERFACE(nsJAR, nsIZipReader)
+NS_IMPL_ADDREF(nsJAR)
+
+// Custom Release method works with nsZipReaderCache...
+// Release might be called from multi-thread, we have to
+// take this function carefully to avoid delete-after-use.
+MozExternalRefCountType nsJAR::Release(void) {
+  nsrefcnt count;
+  MOZ_ASSERT(0 != mRefCnt, "dup release");
+
+  RefPtr<nsZipReaderCache> cache;
+  if (mRefCnt == 2) {  // don't use a lock too frequently
+    // Use a mutex here to guarantee mCache is not racing and the target
+    // instance is still valid to increase ref-count.
+    MutexAutoLock lock(mLock);
+    cache = mCache;
+    mCache = nullptr;
+  }
+  if (cache) {
+    DebugOnly<nsresult> rv = cache->ReleaseZip(this);
+    MOZ_ASSERT(NS_SUCCEEDED(rv), "failed to release zip file");
+  }
+
+  count = --mRefCnt;  // don't access any member variable after this line
+  NS_LOG_RELEASE(this, count, "nsJAR");
+  if (0 == count) {
+    mRefCnt = 1; /* stabilize */
+    /* enable this to find non-threadsafe destructors: */
+    /* NS_ASSERT_OWNINGTHREAD(nsJAR); */
+    delete this;
+    return 0;
+  }
+
+  return count;
+}
+
+//----------------------------------------------
+// nsIZipReader implementation
+//----------------------------------------------
+
+NS_IMETHODIMP
+nsJAR::Open(nsIFile* zipFile) {
+  NS_ENSURE_ARG_POINTER(zipFile);
+  if (mOpened) return NS_ERROR_FAILURE;  // Already open!
+
+  mZipFile = zipFile;
+  mOuterZipEntry.Truncate();
+  mOpened = true;
+
+  // The omnijar is special, it is opened early on and closed late
+  // this avoids reopening it
+  RefPtr<nsZipArchive> zip = mozilla::Omnijar::GetReader(zipFile);
+  if (zip) {
+    mZip = zip;
+    mSkipArchiveClosing = true;
+    return NS_OK;
+  }
+  return mZip->OpenArchive(zipFile);
+}
+
+NS_IMETHODIMP
+nsJAR::OpenInner(nsIZipReader* aZipReader, const nsACString& aZipEntry) {
+  NS_ENSURE_ARG_POINTER(aZipReader);
+  if (mOpened) return NS_ERROR_FAILURE;  // Already open!
+
+  nsJAR* outerJAR = static_cast<nsJAR*>(aZipReader);
+  RefPtr<nsZipArchive> innerZip =
+      mozilla::Omnijar::GetInnerReader(outerJAR->mZipFile, aZipEntry);
+  if (innerZip) {
+    mOpened = true;
+    mZip = innerZip;
+    mSkipArchiveClosing = true;
+    return NS_OK;
+  }
+
+  bool exist;
+  nsresult rv = aZipReader->HasEntry(aZipEntry, &exist);
+  NS_ENSURE_SUCCESS(rv, rv);
+  NS_ENSURE_TRUE(exist, NS_ERROR_FILE_NOT_FOUND);
+
+  rv = aZipReader->GetFile(getter_AddRefs(mZipFile));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mOpened = true;
+
+  mOuterZipEntry.Assign(aZipEntry);
+
+  RefPtr<nsZipHandle> handle;
+  rv = nsZipHandle::Init(static_cast<nsJAR*>(aZipReader)->mZip.get(),
+                         PromiseFlatCString(aZipEntry).get(),
+                         getter_AddRefs(handle));
+  if (NS_FAILED(rv)) return rv;
+
+  return mZip->OpenArchive(handle);
+}
+
+NS_IMETHODIMP
+nsJAR::OpenMemory(void* aData, uint32_t aLength) {
+  NS_ENSURE_ARG_POINTER(aData);
+  if (mOpened) return NS_ERROR_FAILURE;  // Already open!
+
+  mOpened = true;
+
+  RefPtr<nsZipHandle> handle;
+  nsresult rv = nsZipHandle::Init(static_cast<uint8_t*>(aData), aLength,
+                                  getter_AddRefs(handle));
+  if (NS_FAILED(rv)) return rv;
+
+  return mZip->OpenArchive(handle);
+}
+
+NS_IMETHODIMP
+nsJAR::GetFile(nsIFile** result) {
+  *result = mZipFile;
+  NS_IF_ADDREF(*result);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsJAR::Close() {
+  if (!mOpened) {
+    return NS_ERROR_FAILURE;  // Never opened or already closed.
+  }
+
+  mOpened = false;
+
+  if (mSkipArchiveClosing) {
+    // Reset state, but don't close the omnijar because we did not open it.
+    mSkipArchiveClosing = false;
+    mZip = new nsZipArchive();
+    return NS_OK;
+  }
+
+  return mZip->CloseArchive();
+}
+
+NS_IMETHODIMP
+nsJAR::Test(const nsACString& aEntryName) {
+  return mZip->Test(
+      aEntryName.IsEmpty() ? nullptr : PromiseFlatCString(aEntryName).get());
+}
+
+NS_IMETHODIMP
+nsJAR::Extract(const nsACString& aEntryName, nsIFile* outFile) {
+  // nsZipArchive and zlib are not thread safe
+  // we need to use a lock to prevent bug #51267
+  MutexAutoLock lock(mLock);
+
+  nsZipItem* item = mZip->GetItem(PromiseFlatCString(aEntryName).get());
+  NS_ENSURE_TRUE(item, NS_ERROR_FILE_TARGET_DOES_NOT_EXIST);
+
+  // Remove existing file or directory so we set permissions correctly.
+  // If it's a directory that already exists and contains files, throw
+  // an exception and return.
+
+  nsresult rv = outFile->Remove(false);
+  if (rv == NS_ERROR_FILE_DIR_NOT_EMPTY || rv == NS_ERROR_FAILURE) return rv;
+
+  if (item->IsDirectory()) {
+    rv = outFile->Create(nsIFile::DIRECTORY_TYPE, item->Mode());
+    // XXX Do this in nsZipArchive?  It would be nice to keep extraction
+    // XXX code completely there, but that would require a way to get a
+    // XXX PRDir from outFile.
+  } else {
+    PRFileDesc* fd;
+    rv = outFile->OpenNSPRFileDesc(PR_WRONLY | PR_CREATE_FILE, item->Mode(),
+                                   &fd);
+    if (NS_FAILED(rv)) return rv;
+
+    // ExtractFile also closes the fd handle and resolves the symlink if needed
+    rv = mZip->ExtractFile(item, outFile, fd);
+  }
+  if (NS_FAILED(rv)) return rv;
+
+  // nsIFile needs milliseconds, while prtime is in microseconds.
+  // non-fatal if this fails, ignore errors
+  outFile->SetLastModifiedTime(item->LastModTime() / PR_USEC_PER_MSEC);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsJAR::GetEntry(const nsACString& aEntryName, nsIZipEntry** result) {
+  nsZipItem* zipItem = mZip->GetItem(PromiseFlatCString(aEntryName).get());
+  NS_ENSURE_TRUE(zipItem, NS_ERROR_FILE_TARGET_DOES_NOT_EXIST);
+
+  nsJARItem* jarItem = new nsJARItem(zipItem);
+
+  NS_ADDREF(*result = jarItem);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsJAR::HasEntry(const nsACString& aEntryName, bool* result) {
+  *result = mZip->GetItem(PromiseFlatCString(aEntryName).get()) != nullptr;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsJAR::FindEntries(const nsACString& aPattern,
+                   nsIUTF8StringEnumerator** result) {
+  NS_ENSURE_ARG_POINTER(result);
+
+  nsZipFind* find;
+  nsresult rv = mZip->FindInit(
+      aPattern.IsEmpty() ? nullptr : PromiseFlatCString(aPattern).get(), &find);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsIUTF8StringEnumerator* zipEnum = new nsJAREnumerator(find);
+
+  NS_ADDREF(*result = zipEnum);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsJAR::GetInputStream(const nsACString& aFilename, nsIInputStream** result) {
+  return GetInputStreamWithSpec(""_ns, aFilename, result);
+}
+
+NS_IMETHODIMP
+nsJAR::GetInputStreamWithSpec(const nsACString& aJarDirSpec,
+                              const nsACString& aEntryName,
+                              nsIInputStream** result) {
+  NS_ENSURE_ARG_POINTER(result);
+
+  // Watch out for the jar:foo.zip!/ (aDir is empty) top-level special case!
+  nsZipItem* item = nullptr;
+  const nsCString& entry = PromiseFlatCString(aEntryName);
+  if (*entry.get()) {
+    // First check if item exists in jar
+    item = mZip->GetItem(entry.get());
+    if (!item) return NS_ERROR_FILE_TARGET_DOES_NOT_EXIST;
+  }
+  nsJARInputStream* jis = new nsJARInputStream();
+  // addref now so we can call InitFile/InitDirectory()
+  NS_ADDREF(*result = jis);
+
+  nsresult rv = NS_OK;
+  if (!item || item->IsDirectory()) {
+    rv = jis->InitDirectory(this, aJarDirSpec, entry.get());
+  } else {
+    rv = jis->InitFile(this, item);
+  }
+  if (NS_FAILED(rv)) {
+    NS_RELEASE(*result);
+  }
+  return rv;
+}
+
+nsresult nsJAR::GetJarPath(nsACString& aResult) {
+  NS_ENSURE_ARG_POINTER(mZipFile);
+
+  return mZipFile->GetPersistentDescriptor(aResult);
+}
+
+nsresult nsJAR::GetNSPRFileDesc(PRFileDesc** aNSPRFileDesc) {
+  if (!aNSPRFileDesc) {
+    return NS_ERROR_ILLEGAL_VALUE;
+  }
+  *aNSPRFileDesc = nullptr;
+
+  if (!mZip) {
+    return NS_ERROR_FAILURE;
+  }
+
+  RefPtr<nsZipHandle> handle = mZip->GetFD();
+  if (!handle) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return handle->GetNSPRFileDesc(aNSPRFileDesc);
+}
+
+//----------------------------------------------
+// nsJAR private implementation
+//----------------------------------------------
+nsresult nsJAR::LoadEntry(const nsACString& aFilename, nsCString& aBuf) {
+  //-- Get a stream for reading the file
+  nsresult rv;
+  nsCOMPtr<nsIInputStream> manifestStream;
+  rv = GetInputStream(aFilename, getter_AddRefs(manifestStream));
+  if (NS_FAILED(rv)) return NS_ERROR_FILE_TARGET_DOES_NOT_EXIST;
+
+  //-- Read the manifest file into memory
+  char* buf;
+  uint64_t len64;
+  rv = manifestStream->Available(&len64);
+  if (NS_FAILED(rv)) return rv;
+  NS_ENSURE_TRUE(len64 < UINT32_MAX, NS_ERROR_FILE_CORRUPTED);  // bug 164695
+  uint32_t len = (uint32_t)len64;
+  buf = (char*)malloc(len + 1);
+  if (!buf) return NS_ERROR_OUT_OF_MEMORY;
+  uint32_t bytesRead;
+  rv = manifestStream->Read(buf, len, &bytesRead);
+  if (bytesRead != len) {
+    rv = NS_ERROR_FILE_CORRUPTED;
+  }
+  if (NS_FAILED(rv)) {
+    free(buf);
+    return rv;
+  }
+  buf[len] = '\0';  // Null-terminate the buffer
+  aBuf.Adopt(buf, len);
+  return NS_OK;
+}
+
+int32_t nsJAR::ReadLine(const char** src) {
+  if (!*src) {
+    return 0;
+  }
+
+  //--Moves pointer to beginning of next line and returns line length
+  //  not including CR/LF.
+  int32_t length;
+  char* eol = PL_strpbrk(*src, "\r\n");
+
+  if (eol == nullptr)  // Probably reached end of file before newline
+  {
+    length = strlen(*src);
+    if (length == 0)  // immediate end-of-file
+      *src = nullptr;
+    else  // some data left on this line
+      *src += length;
+  } else {
+    length = eol - *src;
+    if (eol[0] == '\r' && eol[1] == '\n')  // CR LF, so skip 2
+      *src = eol + 2;
+    else  // Either CR or LF, so skip 1
+      *src = eol + 1;
+  }
+  return length;
+}
+
+NS_IMPL_ISUPPORTS(nsJAREnumerator, nsIUTF8StringEnumerator, nsIStringEnumerator)
+
+//----------------------------------------------
+// nsJAREnumerator::HasMore
+//----------------------------------------------
+NS_IMETHODIMP
+nsJAREnumerator::HasMore(bool* aResult) {
+  // try to get the next element
+  if (!mName) {
+    NS_ASSERTION(mFind, "nsJAREnumerator: Missing zipFind.");
+    nsresult rv = mFind->FindNext(&mName, &mNameLen);
+    if (rv == NS_ERROR_FILE_TARGET_DOES_NOT_EXIST) {
+      *aResult = false;  // No more matches available
+      return NS_OK;
+    }
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);  // no error translation
+  }
+
+  *aResult = true;
+  return NS_OK;
+}
+
+//----------------------------------------------
+// nsJAREnumerator::GetNext
+//----------------------------------------------
+NS_IMETHODIMP
+nsJAREnumerator::GetNext(nsACString& aResult) {
+  // check if the current item is "stale"
+  if (!mName) {
+    bool bMore;
+    nsresult rv = HasMore(&bMore);
+    if (NS_FAILED(rv) || !bMore)
+      return NS_ERROR_FAILURE;  // no error translation
+  }
+  aResult.Assign(mName, mNameLen);
+  mName = 0;  // we just gave this one away
+  return NS_OK;
+}
+
+NS_IMPL_ISUPPORTS(nsJARItem, nsIZipEntry)
+
+nsJARItem::nsJARItem(nsZipItem* aZipItem)
+    : mSize(aZipItem->Size()),
+      mRealsize(aZipItem->RealSize()),
+      mCrc32(aZipItem->CRC32()),
+      mLastModTime(aZipItem->LastModTime()),
+      mCompression(aZipItem->Compression()),
+      mPermissions(aZipItem->Mode()),
+      mIsDirectory(aZipItem->IsDirectory()),
+      mIsSynthetic(aZipItem->isSynthetic) {}
+
+//------------------------------------------
+// nsJARItem::GetCompression
+//------------------------------------------
+NS_IMETHODIMP
+nsJARItem::GetCompression(uint16_t* aCompression) {
+  NS_ENSURE_ARG_POINTER(aCompression);
+
+  *aCompression = mCompression;
+  return NS_OK;
+}
+
+//------------------------------------------
+// nsJARItem::GetSize
+//------------------------------------------
+NS_IMETHODIMP
+nsJARItem::GetSize(uint32_t* aSize) {
+  NS_ENSURE_ARG_POINTER(aSize);
+
+  *aSize = mSize;
+  return NS_OK;
+}
+
+//------------------------------------------
+// nsJARItem::GetRealSize
+//------------------------------------------
+NS_IMETHODIMP
+nsJARItem::GetRealSize(uint32_t* aRealsize) {
+  NS_ENSURE_ARG_POINTER(aRealsize);
+
+  *aRealsize = mRealsize;
+  return NS_OK;
+}
+
+//------------------------------------------
+// nsJARItem::GetCrc32
+//------------------------------------------
+NS_IMETHODIMP
+nsJARItem::GetCRC32(uint32_t* aCrc32) {
+  NS_ENSURE_ARG_POINTER(aCrc32);
+
+  *aCrc32 = mCrc32;
+  return NS_OK;
+}
+
+//------------------------------------------
+// nsJARItem::GetIsDirectory
+//------------------------------------------
+NS_IMETHODIMP
+nsJARItem::GetIsDirectory(bool* aIsDirectory) {
+  NS_ENSURE_ARG_POINTER(aIsDirectory);
+
+  *aIsDirectory = mIsDirectory;
+  return NS_OK;
+}
+
+//------------------------------------------
+// nsJARItem::GetIsSynthetic
+//------------------------------------------
+NS_IMETHODIMP
+nsJARItem::GetIsSynthetic(bool* aIsSynthetic) {
+  NS_ENSURE_ARG_POINTER(aIsSynthetic);
+
+  *aIsSynthetic = mIsSynthetic;
+  return NS_OK;
+}
+
+//------------------------------------------
+// nsJARItem::GetLastModifiedTime
+//------------------------------------------
+NS_IMETHODIMP
+nsJARItem::GetLastModifiedTime(PRTime* aLastModTime) {
+  NS_ENSURE_ARG_POINTER(aLastModTime);
+
+  *aLastModTime = mLastModTime;
+  return NS_OK;
+}
+
+//------------------------------------------
+// nsJARItem::GetPermissions
+//------------------------------------------
+NS_IMETHODIMP
+nsJARItem::GetPermissions(uint32_t* aPermissions) {
+  NS_ENSURE_ARG_POINTER(aPermissions);
+
+  *aPermissions = mPermissions;
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIZipReaderCache
+
+NS_IMPL_ISUPPORTS(nsZipReaderCache, nsIZipReaderCache, nsIObserver,
+                  nsISupportsWeakReference)
+
+nsZipReaderCache::nsZipReaderCache()
+    : mLock("nsZipReaderCache.mLock"),
+      mCacheSize(0),
+      mZips()
+#ifdef ZIP_CACHE_HIT_RATE
+      ,
+      mZipCacheLookups(0),
+      mZipCacheHits(0),
+      mZipCacheFlushes(0),
+      mZipSyncMisses(0)
+#endif
+{
+}
+
+NS_IMETHODIMP
+nsZipReaderCache::Init(uint32_t cacheSize) {
+  mCacheSize = cacheSize;
+
+  // Register as a memory pressure observer
+  nsCOMPtr<nsIObserverService> os =
+      do_GetService("@mozilla.org/observer-service;1");
+  if (os) {
+    os->AddObserver(this, "memory-pressure", true);
+    os->AddObserver(this, "chrome-flush-caches", true);
+    os->AddObserver(this, "flush-cache-entry", true);
+  }
+  // ignore failure of the observer registration.
+
+  return NS_OK;
+}
+
+nsZipReaderCache::~nsZipReaderCache() {
+  for (auto iter = mZips.Iter(); !iter.Done(); iter.Next()) {
+    iter.UserData()->SetZipReaderCache(nullptr);
+  }
+
+#ifdef ZIP_CACHE_HIT_RATE
+  printf(
+      "nsZipReaderCache size=%d hits=%d lookups=%d rate=%f%% flushes=%d missed "
+      "%d\n",
+      mCacheSize, mZipCacheHits, mZipCacheLookups,
+      (float)mZipCacheHits / mZipCacheLookups, mZipCacheFlushes,
+      mZipSyncMisses);
+#endif
+}
+
+NS_IMETHODIMP
+nsZipReaderCache::IsCached(nsIFile* zipFile, bool* aResult) {
+  NS_ENSURE_ARG_POINTER(zipFile);
+  nsresult rv;
+  MutexAutoLock lock(mLock);
+
+  nsAutoCString uri;
+  rv = zipFile->GetPersistentDescriptor(uri);
+  if (NS_FAILED(rv)) return rv;
+
+  uri.InsertLiteral("file:", 0);
+
+  *aResult = mZips.Contains(uri);
+  return NS_OK;
+}
+
+nsresult nsZipReaderCache::GetZip(nsIFile* zipFile, nsIZipReader** result,
+                                  bool failOnMiss) {
+  NS_ENSURE_ARG_POINTER(zipFile);
+  nsresult rv;
+  MutexAutoLock lock(mLock);
+
+#ifdef ZIP_CACHE_HIT_RATE
+  mZipCacheLookups++;
+#endif
+
+  nsAutoCString uri;
+  rv = zipFile->GetPersistentDescriptor(uri);
+  if (NS_FAILED(rv)) return rv;
+
+  uri.InsertLiteral("file:", 0);
+
+  RefPtr<nsJAR> zip;
+  mZips.Get(uri, getter_AddRefs(zip));
+  if (zip) {
+#ifdef ZIP_CACHE_HIT_RATE
+    mZipCacheHits++;
+#endif
+    zip->ClearReleaseTime();
+  } else {
+    if (failOnMiss) {
+      return NS_ERROR_CACHE_KEY_NOT_FOUND;
+    }
+
+    zip = new nsJAR();
+    zip->SetZipReaderCache(this);
+    rv = zip->Open(zipFile);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    MOZ_ASSERT(!mZips.Contains(uri));
+    mZips.Put(uri, RefPtr{zip});
+  }
+  zip.forget(result);
+  return rv;
+}
+
+NS_IMETHODIMP
+nsZipReaderCache::GetZipIfCached(nsIFile* zipFile, nsIZipReader** result) {
+  return GetZip(zipFile, result, true);
+}
+
+NS_IMETHODIMP
+nsZipReaderCache::GetZip(nsIFile* zipFile, nsIZipReader** result) {
+  return GetZip(zipFile, result, false);
+}
+
+NS_IMETHODIMP
+nsZipReaderCache::GetInnerZip(nsIFile* zipFile, const nsACString& entry,
+                              nsIZipReader** result) {
+  NS_ENSURE_ARG_POINTER(zipFile);
+
+  nsCOMPtr<nsIZipReader> outerZipReader;
+  nsresult rv = GetZip(zipFile, getter_AddRefs(outerZipReader));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  MutexAutoLock lock(mLock);
+
+#ifdef ZIP_CACHE_HIT_RATE
+  mZipCacheLookups++;
+#endif
+
+  nsAutoCString uri;
+  rv = zipFile->GetPersistentDescriptor(uri);
+  if (NS_FAILED(rv)) return rv;
+
+  uri.InsertLiteral("jar:", 0);
+  uri.AppendLiteral("!/");
+  uri.Append(entry);
+
+  RefPtr<nsJAR> zip;
+  mZips.Get(uri, getter_AddRefs(zip));
+  if (zip) {
+#ifdef ZIP_CACHE_HIT_RATE
+    mZipCacheHits++;
+#endif
+    zip->ClearReleaseTime();
+  } else {
+    zip = new nsJAR();
+    zip->SetZipReaderCache(this);
+
+    rv = zip->OpenInner(outerZipReader, entry);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    MOZ_ASSERT(!mZips.Contains(uri));
+    mZips.Put(uri, RefPtr{zip});
+  }
+  zip.forget(result);
+  return rv;
+}
+
+NS_IMETHODIMP
+nsZipReaderCache::GetFd(nsIFile* zipFile, PRFileDesc** aRetVal) {
+#if defined(XP_WIN)
+  MOZ_CRASH("Not implemented");
+  return NS_ERROR_NOT_IMPLEMENTED;
+#else
+  if (!zipFile) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsresult rv;
+  nsAutoCString uri;
+  rv = zipFile->GetPersistentDescriptor(uri);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  uri.InsertLiteral("file:", 0);
+
+  MutexAutoLock lock(mLock);
+  RefPtr<nsJAR> zip;
+  mZips.Get(uri, getter_AddRefs(zip));
+  if (!zip) {
+    return NS_ERROR_FAILURE;
+  }
+
+  zip->ClearReleaseTime();
+  rv = zip->GetNSPRFileDesc(aRetVal);
+  // Do this to avoid possible deadlock on mLock with ReleaseZip().
+  {
+    MutexAutoUnlock unlock(mLock);
+    zip = nullptr;
+  }
+  return rv;
+#endif /* XP_WIN */
+}
+
+nsresult nsZipReaderCache::ReleaseZip(nsJAR* zip) {
+  nsresult rv;
+  MutexAutoLock lock(mLock);
+
+  // It is possible that two thread compete for this zip. The dangerous
+  // case is where one thread Releases the zip and discovers that the ref
+  // count has gone to one. Before it can call this ReleaseZip method
+  // another thread calls our GetZip method. The ref count goes to two. That
+  // second thread then Releases the zip and the ref count goes to one. It
+  // then tries to enter this ReleaseZip method and blocks while the first
+  // thread is still here. The first thread continues and remove the zip from
+  // the cache and calls its Release method sending the ref count to 0 and
+  // deleting the zip. However, the second thread is still blocked at the
+  // start of ReleaseZip, but the 'zip' param now hold a reference to a
+  // deleted zip!
+  //
+  // So, we are going to try safeguarding here by searching our hashtable while
+  // locked here for the zip. We return fast if it is not found.
+
+  bool found = false;
+  for (auto iter = mZips.Iter(); !iter.Done(); iter.Next()) {
+    if (zip == iter.UserData()) {
+      found = true;
+      break;
+    }
+  }
+
+  if (!found) {
+#ifdef ZIP_CACHE_HIT_RATE
+    mZipSyncMisses++;
+#endif
+    return NS_OK;
+  }
+
+  zip->SetReleaseTime();
+
+  if (mZips.Count() <= mCacheSize) return NS_OK;
+
+  // Find the oldest zip.
+  nsJAR* oldest = nullptr;
+  for (auto iter = mZips.Iter(); !iter.Done(); iter.Next()) {
+    nsJAR* current = iter.UserData();
+    PRIntervalTime currentReleaseTime = current->GetReleaseTime();
+    if (currentReleaseTime != PR_INTERVAL_NO_TIMEOUT) {
+      if (oldest == nullptr || currentReleaseTime < oldest->GetReleaseTime()) {
+        oldest = current;
+      }
+    }
+  }
+
+  // Because of the craziness above it is possible that there is no zip that
+  // needs removing.
+  if (!oldest) return NS_OK;
+
+#ifdef ZIP_CACHE_HIT_RATE
+  mZipCacheFlushes++;
+#endif
+
+  // remove from hashtable
+  nsAutoCString uri;
+  rv = oldest->GetJarPath(uri);
+  if (NS_FAILED(rv)) return rv;
+
+  if (oldest->mOuterZipEntry.IsEmpty()) {
+    uri.InsertLiteral("file:", 0);
+  } else {
+    uri.InsertLiteral("jar:", 0);
+    uri.AppendLiteral("!/");
+    uri.Append(oldest->mOuterZipEntry);
+  }
+
+  // Retrieving and removing the JAR must be done without an extra AddRef
+  // and Release, or we'll trigger nsJAR::Release's magic refcount 1 case
+  // an extra time and trigger a deadlock.
+  RefPtr<nsJAR> removed;
+  mZips.Remove(uri, getter_AddRefs(removed));
+  NS_ASSERTION(removed, "botched");
+  NS_ASSERTION(oldest == removed, "removed wrong entry");
+
+  if (removed) removed->SetZipReaderCache(nullptr);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsZipReaderCache::Observe(nsISupports* aSubject, const char* aTopic,
+                          const char16_t* aSomeData) {
+  if (strcmp(aTopic, "memory-pressure") == 0) {
+    MutexAutoLock lock(mLock);
+    for (auto iter = mZips.Iter(); !iter.Done(); iter.Next()) {
+      RefPtr<nsJAR>& current = iter.Data();
+      if (current->GetReleaseTime() != PR_INTERVAL_NO_TIMEOUT) {
+        current->SetZipReaderCache(nullptr);
+        iter.Remove();
+      }
+    }
+  } else if (strcmp(aTopic, "chrome-flush-caches") == 0) {
+    MutexAutoLock lock(mLock);
+    for (auto iter = mZips.Iter(); !iter.Done(); iter.Next()) {
+      iter.UserData()->SetZipReaderCache(nullptr);
+    }
+    mZips.Clear();
+  } else if (strcmp(aTopic, "flush-cache-entry") == 0) {
+    nsCOMPtr<nsIFile> file;
+    if (aSubject) {
+      file = do_QueryInterface(aSubject);
+    } else if (aSomeData) {
+      nsDependentString fileName(aSomeData);
+      Unused << NS_NewLocalFile(fileName, false, getter_AddRefs(file));
+    }
+
+    if (!file) return NS_OK;
+
+    nsAutoCString uri;
+    if (NS_FAILED(file->GetPersistentDescriptor(uri))) return NS_OK;
+
+    uri.InsertLiteral("file:", 0);
+
+    MutexAutoLock lock(mLock);
+
+    RefPtr<nsJAR> zip;
+    mZips.Get(uri, getter_AddRefs(zip));
+    if (!zip) return NS_OK;
+
+#ifdef ZIP_CACHE_HIT_RATE
+    mZipCacheFlushes++;
+#endif
+
+    zip->SetZipReaderCache(nullptr);
+
+    mZips.Remove(uri);
+  }
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////