summaryrefslogtreecommitdiffstats
path: root/netwerk/cache/nsDiskCacheBinding.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'netwerk/cache/nsDiskCacheBinding.cpp')
-rw-r--r--netwerk/cache/nsDiskCacheBinding.cpp371
1 files changed, 371 insertions, 0 deletions
diff --git a/netwerk/cache/nsDiskCacheBinding.cpp b/netwerk/cache/nsDiskCacheBinding.cpp
new file mode 100644
index 000000000..cdc2606e6
--- /dev/null
+++ b/netwerk/cache/nsDiskCacheBinding.cpp
@@ -0,0 +1,371 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * 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 "mozilla/MemoryReporting.h"
+#include "nsCache.h"
+#include <limits.h>
+
+#include "nscore.h"
+#include "nsDiskCacheBinding.h"
+#include "nsCacheService.h"
+
+using namespace mozilla;
+
+/******************************************************************************
+ * static hash table callback functions
+ *
+ *****************************************************************************/
+struct HashTableEntry : PLDHashEntryHdr {
+ nsDiskCacheBinding * mBinding;
+};
+
+
+static PLDHashNumber
+HashKey(const void *key)
+{
+ return (PLDHashNumber) NS_PTR_TO_INT32(key);
+}
+
+
+static bool
+MatchEntry(const PLDHashEntryHdr * header,
+ const void * key)
+{
+ HashTableEntry * hashEntry = (HashTableEntry *) header;
+ return (hashEntry->mBinding->mRecord.HashNumber() == (PLDHashNumber) NS_PTR_TO_INT32(key));
+}
+
+static void
+MoveEntry(PLDHashTable * /* table */,
+ const PLDHashEntryHdr * src,
+ PLDHashEntryHdr * dst)
+{
+ ((HashTableEntry *)dst)->mBinding = ((HashTableEntry *)src)->mBinding;
+}
+
+
+static void
+ClearEntry(PLDHashTable * /* table */,
+ PLDHashEntryHdr * header)
+{
+ ((HashTableEntry *)header)->mBinding = nullptr;
+}
+
+
+/******************************************************************************
+ * Utility Functions
+ *****************************************************************************/
+nsDiskCacheBinding *
+GetCacheEntryBinding(nsCacheEntry * entry)
+{
+ return (nsDiskCacheBinding *) entry->Data();
+}
+
+
+/******************************************************************************
+ * nsDiskCacheBinding
+ *****************************************************************************/
+
+NS_IMPL_ISUPPORTS0(nsDiskCacheBinding)
+
+nsDiskCacheBinding::nsDiskCacheBinding(nsCacheEntry* entry, nsDiskCacheRecord * record)
+ : mCacheEntry(entry)
+ , mStreamIO(nullptr)
+ , mDeactivateEvent(nullptr)
+{
+ NS_ASSERTION(record->ValidRecord(), "bad record");
+ PR_INIT_CLIST(this);
+ mRecord = *record;
+ mDoomed = entry->IsDoomed();
+ mGeneration = record->Generation(); // 0 == uninitialized, or data & meta using block files
+}
+
+nsDiskCacheBinding::~nsDiskCacheBinding()
+{
+ // Grab the cache lock since the binding is stored in nsCacheEntry::mData
+ // and it is released using nsCacheService::ReleaseObject_Locked() which
+ // releases the object outside the cache lock.
+ nsCacheServiceAutoLock lock;
+
+ NS_ASSERTION(PR_CLIST_IS_EMPTY(this), "binding deleted while still on list");
+ if (!PR_CLIST_IS_EMPTY(this))
+ PR_REMOVE_LINK(this); // XXX why are we still on a list?
+
+ // sever streamIO/binding link
+ if (mStreamIO) {
+ if (NS_FAILED(mStreamIO->ClearBinding()))
+ nsCacheService::DoomEntry(mCacheEntry);
+ NS_RELEASE(mStreamIO);
+ }
+}
+
+nsresult
+nsDiskCacheBinding::EnsureStreamIO()
+{
+ if (!mStreamIO) {
+ mStreamIO = new nsDiskCacheStreamIO(this);
+ if (!mStreamIO) return NS_ERROR_OUT_OF_MEMORY;
+ NS_ADDREF(mStreamIO);
+ }
+ return NS_OK;
+}
+
+
+/******************************************************************************
+ * nsDiskCacheBindery
+ *
+ * Keeps track of bound disk cache entries to detect for collisions.
+ *
+ *****************************************************************************/
+
+const PLDHashTableOps nsDiskCacheBindery::ops =
+{
+ HashKey,
+ MatchEntry,
+ MoveEntry,
+ ClearEntry
+};
+
+
+nsDiskCacheBindery::nsDiskCacheBindery()
+ : table(&ops, sizeof(HashTableEntry), kInitialTableLength)
+ , initialized(false)
+{
+}
+
+
+nsDiskCacheBindery::~nsDiskCacheBindery()
+{
+ Reset();
+}
+
+
+void
+nsDiskCacheBindery::Init()
+{
+ table.ClearAndPrepareForLength(kInitialTableLength);
+ initialized = true;
+}
+
+void
+nsDiskCacheBindery::Reset()
+{
+ if (initialized) {
+ table.ClearAndPrepareForLength(kInitialTableLength);
+ initialized = false;
+ }
+}
+
+
+nsDiskCacheBinding *
+nsDiskCacheBindery::CreateBinding(nsCacheEntry * entry,
+ nsDiskCacheRecord * record)
+{
+ NS_ASSERTION(initialized, "nsDiskCacheBindery not initialized");
+ nsCOMPtr<nsISupports> data = entry->Data();
+ if (data) {
+ NS_ERROR("cache entry already has bind data");
+ return nullptr;
+ }
+
+ nsDiskCacheBinding * binding = new nsDiskCacheBinding(entry, record);
+ if (!binding) return nullptr;
+
+ // give ownership of the binding to the entry
+ entry->SetData(binding);
+
+ // add binding to collision detection system
+ nsresult rv = AddBinding(binding);
+ if (NS_FAILED(rv)) {
+ entry->SetData(nullptr);
+ return nullptr;
+ }
+
+ return binding;
+}
+
+
+/**
+ * FindActiveEntry : to find active colliding entry so we can doom it
+ */
+nsDiskCacheBinding *
+nsDiskCacheBindery::FindActiveBinding(uint32_t hashNumber)
+{
+ NS_ASSERTION(initialized, "nsDiskCacheBindery not initialized");
+ // find hash entry for key
+ auto hashEntry = static_cast<HashTableEntry*>
+ (table.Search((void*)(uintptr_t)hashNumber));
+ if (!hashEntry) return nullptr;
+
+ // walk list looking for active entry
+ NS_ASSERTION(hashEntry->mBinding, "hash entry left with no binding");
+ nsDiskCacheBinding * binding = hashEntry->mBinding;
+ while (binding->mCacheEntry->IsDoomed()) {
+ binding = (nsDiskCacheBinding *)PR_NEXT_LINK(binding);
+ if (binding == hashEntry->mBinding) return nullptr;
+ }
+ return binding;
+}
+
+
+/**
+ * AddBinding
+ *
+ * Called from FindEntry() if we read an entry off of disk
+ * - it may already have a generation number
+ * - a generation number conflict is an error
+ *
+ * Called from BindEntry()
+ * - a generation number needs to be assigned
+ */
+nsresult
+nsDiskCacheBindery::AddBinding(nsDiskCacheBinding * binding)
+{
+ NS_ENSURE_ARG_POINTER(binding);
+ NS_ASSERTION(initialized, "nsDiskCacheBindery not initialized");
+
+ // find hash entry for key
+ auto hashEntry = static_cast<HashTableEntry*>
+ (table.Add((void*)(uintptr_t)binding->mRecord.HashNumber(), fallible));
+ if (!hashEntry)
+ return NS_ERROR_OUT_OF_MEMORY;
+
+ if (hashEntry->mBinding == nullptr) {
+ hashEntry->mBinding = binding;
+ if (binding->mGeneration == 0)
+ binding->mGeneration = 1; // if generation uninitialized, set it to 1
+
+ return NS_OK;
+ }
+
+
+ // insert binding in generation order
+ nsDiskCacheBinding * p = hashEntry->mBinding;
+ bool calcGeneration = (binding->mGeneration == 0); // do we need to calculate generation?
+ if (calcGeneration) binding->mGeneration = 1; // initialize to 1 if uninitialized
+ while (1) {
+
+ if (binding->mGeneration < p->mGeneration) {
+ // here we are
+ PR_INSERT_BEFORE(binding, p);
+ if (hashEntry->mBinding == p)
+ hashEntry->mBinding = binding;
+ break;
+ }
+
+ if (binding->mGeneration == p->mGeneration) {
+ if (calcGeneration) ++binding->mGeneration; // try the next generation
+ else {
+ NS_ERROR("### disk cache: generations collide!");
+ return NS_ERROR_UNEXPECTED;
+ }
+ }
+
+ p = (nsDiskCacheBinding *)PR_NEXT_LINK(p);
+ if (p == hashEntry->mBinding) {
+ // end of line: insert here or die
+ p = (nsDiskCacheBinding *)PR_PREV_LINK(p); // back up and check generation
+ if (p->mGeneration == 255) {
+ NS_WARNING("### disk cache: generation capacity at full");
+ return NS_ERROR_UNEXPECTED;
+ }
+ PR_INSERT_BEFORE(binding, hashEntry->mBinding);
+ break;
+ }
+ }
+ return NS_OK;
+}
+
+
+/**
+ * RemoveBinding : remove binding from collision detection on deactivation
+ */
+void
+nsDiskCacheBindery::RemoveBinding(nsDiskCacheBinding * binding)
+{
+ NS_ASSERTION(initialized, "nsDiskCacheBindery not initialized");
+ if (!initialized) return;
+
+ void* key = (void *)(uintptr_t)binding->mRecord.HashNumber();
+ auto hashEntry =
+ static_cast<HashTableEntry*>(table.Search((void*)(uintptr_t) key));
+ if (!hashEntry) {
+ NS_WARNING("### disk cache: binding not in hashtable!");
+ return;
+ }
+
+ if (binding == hashEntry->mBinding) {
+ if (PR_CLIST_IS_EMPTY(binding)) {
+ // remove this hash entry
+ table.Remove((void*)(uintptr_t) binding->mRecord.HashNumber());
+ return;
+
+ } else {
+ // promote next binding to head, and unlink this binding
+ hashEntry->mBinding = (nsDiskCacheBinding *)PR_NEXT_LINK(binding);
+ }
+ }
+ PR_REMOVE_AND_INIT_LINK(binding);
+}
+
+/**
+ * ActiveBindings: return true if any bindings have open descriptors.
+ */
+bool
+nsDiskCacheBindery::ActiveBindings()
+{
+ NS_ASSERTION(initialized, "nsDiskCacheBindery not initialized");
+ if (!initialized) return false;
+
+ for (auto iter = table.Iter(); !iter.Done(); iter.Next()) {
+ auto entry = static_cast<HashTableEntry*>(iter.Get());
+ nsDiskCacheBinding* binding = entry->mBinding;
+ nsDiskCacheBinding* head = binding;
+ do {
+ if (binding->IsActive()) {
+ return true;
+ }
+ binding = (nsDiskCacheBinding *)PR_NEXT_LINK(binding);
+ } while (binding != head);
+ }
+
+ return false;
+}
+
+/**
+ * SizeOfExcludingThis: return the amount of heap memory (bytes) being used by
+ * the bindery.
+ */
+size_t
+nsDiskCacheBindery::SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf)
+{
+ NS_ASSERTION(initialized, "nsDiskCacheBindery not initialized");
+ if (!initialized) return 0;
+
+ size_t size = 0;
+
+ for (auto iter = table.Iter(); !iter.Done(); iter.Next()) {
+ auto entry = static_cast<HashTableEntry*>(iter.Get());
+ nsDiskCacheBinding* binding = entry->mBinding;
+
+ nsDiskCacheBinding* head = binding;
+ do {
+ size += aMallocSizeOf(binding);
+ if (binding->mStreamIO) {
+ size += binding->mStreamIO->SizeOfIncludingThis(aMallocSizeOf);
+ }
+
+ // No good way to get at mDeactivateEvent internals for proper
+ // size, so we use this as an estimate.
+ if (binding->mDeactivateEvent) {
+ size += aMallocSizeOf(binding->mDeactivateEvent);
+ }
+ binding = (nsDiskCacheBinding *)PR_NEXT_LINK(binding);
+ } while (binding != head);
+ }
+
+ return size;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-14 10:38:10 +0000