summaryrefslogtreecommitdiffstats
path: root/libs/utils/BlobCache.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'libs/utils/BlobCache.cpp')
-rw-r--r--libs/utils/BlobCache.cpp378
1 files changed, 0 insertions, 378 deletions
diff --git a/libs/utils/BlobCache.cpp b/libs/utils/BlobCache.cpp
deleted file mode 100644
index be398ee..0000000
--- a/libs/utils/BlobCache.cpp
+++ /dev/null
@@ -1,378 +0,0 @@
-/*
- ** Copyright 2011, The Android Open Source Project
- **
- ** Licensed under the Apache License, Version 2.0 (the "License");
- ** you may not use this file except in compliance with the License.
- ** You may obtain a copy of the License at
- **
- ** http://www.apache.org/licenses/LICENSE-2.0
- **
- ** Unless required by applicable law or agreed to in writing, software
- ** distributed under the License is distributed on an "AS IS" BASIS,
- ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- ** See the License for the specific language governing permissions and
- ** limitations under the License.
- */
-
-#define LOG_TAG "BlobCache"
-//#define LOG_NDEBUG 0
-
-#include <stdlib.h>
-#include <string.h>
-
-#include <utils/BlobCache.h>
-#include <utils/Errors.h>
-#include <utils/Log.h>
-
-namespace android {
-
-// BlobCache::Header::mMagicNumber value
-static const uint32_t blobCacheMagic = '_Bb$';
-
-// BlobCache::Header::mBlobCacheVersion value
-static const uint32_t blobCacheVersion = 1;
-
-// BlobCache::Header::mDeviceVersion value
-static const uint32_t blobCacheDeviceVersion = 1;
-
-BlobCache::BlobCache(size_t maxKeySize, size_t maxValueSize, size_t maxTotalSize):
- mMaxKeySize(maxKeySize),
- mMaxValueSize(maxValueSize),
- mMaxTotalSize(maxTotalSize),
- mTotalSize(0) {
- nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
-#ifdef _WIN32
- srand(now);
-#else
- mRandState[0] = (now >> 0) & 0xFFFF;
- mRandState[1] = (now >> 16) & 0xFFFF;
- mRandState[2] = (now >> 32) & 0xFFFF;
-#endif
- ALOGV("initializing random seed using %lld", now);
-}
-
-void BlobCache::set(const void* key, size_t keySize, const void* value,
- size_t valueSize) {
- if (mMaxKeySize < keySize) {
- ALOGV("set: not caching because the key is too large: %d (limit: %d)",
- keySize, mMaxKeySize);
- return;
- }
- if (mMaxValueSize < valueSize) {
- ALOGV("set: not caching because the value is too large: %d (limit: %d)",
- valueSize, mMaxValueSize);
- return;
- }
- if (mMaxTotalSize < keySize + valueSize) {
- ALOGV("set: not caching because the combined key/value size is too "
- "large: %d (limit: %d)", keySize + valueSize, mMaxTotalSize);
- return;
- }
- if (keySize == 0) {
- ALOGW("set: not caching because keySize is 0");
- return;
- }
- if (valueSize <= 0) {
- ALOGW("set: not caching because valueSize is 0");
- return;
- }
-
- sp<Blob> dummyKey(new Blob(key, keySize, false));
- CacheEntry dummyEntry(dummyKey, NULL);
-
- while (true) {
- ssize_t index = mCacheEntries.indexOf(dummyEntry);
- if (index < 0) {
- // Create a new cache entry.
- sp<Blob> keyBlob(new Blob(key, keySize, true));
- sp<Blob> valueBlob(new Blob(value, valueSize, true));
- size_t newTotalSize = mTotalSize + keySize + valueSize;
- if (mMaxTotalSize < newTotalSize) {
- if (isCleanable()) {
- // Clean the cache and try again.
- clean();
- continue;
- } else {
- ALOGV("set: not caching new key/value pair because the "
- "total cache size limit would be exceeded: %d "
- "(limit: %d)",
- keySize + valueSize, mMaxTotalSize);
- break;
- }
- }
- mCacheEntries.add(CacheEntry(keyBlob, valueBlob));
- mTotalSize = newTotalSize;
- ALOGV("set: created new cache entry with %d byte key and %d byte value",
- keySize, valueSize);
- } else {
- // Update the existing cache entry.
- sp<Blob> valueBlob(new Blob(value, valueSize, true));
- sp<Blob> oldValueBlob(mCacheEntries[index].getValue());
- size_t newTotalSize = mTotalSize + valueSize - oldValueBlob->getSize();
- if (mMaxTotalSize < newTotalSize) {
- if (isCleanable()) {
- // Clean the cache and try again.
- clean();
- continue;
- } else {
- ALOGV("set: not caching new value because the total cache "
- "size limit would be exceeded: %d (limit: %d)",
- keySize + valueSize, mMaxTotalSize);
- break;
- }
- }
- mCacheEntries.editItemAt(index).setValue(valueBlob);
- mTotalSize = newTotalSize;
- ALOGV("set: updated existing cache entry with %d byte key and %d byte "
- "value", keySize, valueSize);
- }
- break;
- }
-}
-
-size_t BlobCache::get(const void* key, size_t keySize, void* value,
- size_t valueSize) {
- if (mMaxKeySize < keySize) {
- ALOGV("get: not searching because the key is too large: %d (limit %d)",
- keySize, mMaxKeySize);
- return 0;
- }
- sp<Blob> dummyKey(new Blob(key, keySize, false));
- CacheEntry dummyEntry(dummyKey, NULL);
- ssize_t index = mCacheEntries.indexOf(dummyEntry);
- if (index < 0) {
- ALOGV("get: no cache entry found for key of size %d", keySize);
- return 0;
- }
-
- // The key was found. Return the value if the caller's buffer is large
- // enough.
- sp<Blob> valueBlob(mCacheEntries[index].getValue());
- size_t valueBlobSize = valueBlob->getSize();
- if (valueBlobSize <= valueSize) {
- ALOGV("get: copying %d bytes to caller's buffer", valueBlobSize);
- memcpy(value, valueBlob->getData(), valueBlobSize);
- } else {
- ALOGV("get: caller's buffer is too small for value: %d (needs %d)",
- valueSize, valueBlobSize);
- }
- return valueBlobSize;
-}
-
-static inline size_t align4(size_t size) {
- return (size + 3) & ~3;
-}
-
-size_t BlobCache::getFlattenedSize() const {
- size_t size = sizeof(Header);
- for (size_t i = 0; i < mCacheEntries.size(); i++) {
- const CacheEntry& e(mCacheEntries[i]);
- sp<Blob> keyBlob = e.getKey();
- sp<Blob> valueBlob = e.getValue();
- size = align4(size);
- size += sizeof(EntryHeader) + keyBlob->getSize() +
- valueBlob->getSize();
- }
- return size;
-}
-
-size_t BlobCache::getFdCount() const {
- return 0;
-}
-
-status_t BlobCache::flatten(void* buffer, size_t size, int fds[], size_t count)
- const {
- if (count != 0) {
- ALOGE("flatten: nonzero fd count: %zu", count);
- return BAD_VALUE;
- }
-
- // Write the cache header
- if (size < sizeof(Header)) {
- ALOGE("flatten: not enough room for cache header");
- return BAD_VALUE;
- }
- Header* header = reinterpret_cast<Header*>(buffer);
- header->mMagicNumber = blobCacheMagic;
- header->mBlobCacheVersion = blobCacheVersion;
- header->mDeviceVersion = blobCacheDeviceVersion;
- header->mNumEntries = mCacheEntries.size();
-
- // Write cache entries
- uint8_t* byteBuffer = reinterpret_cast<uint8_t*>(buffer);
- off_t byteOffset = align4(sizeof(Header));
- for (size_t i = 0; i < mCacheEntries.size(); i++) {
- const CacheEntry& e(mCacheEntries[i]);
- sp<Blob> keyBlob = e.getKey();
- sp<Blob> valueBlob = e.getValue();
- size_t keySize = keyBlob->getSize();
- size_t valueSize = valueBlob->getSize();
-
- size_t entrySize = sizeof(EntryHeader) + keySize + valueSize;
- if (byteOffset + entrySize > size) {
- ALOGE("flatten: not enough room for cache entries");
- return BAD_VALUE;
- }
-
- EntryHeader* eheader = reinterpret_cast<EntryHeader*>(
- &byteBuffer[byteOffset]);
- eheader->mKeySize = keySize;
- eheader->mValueSize = valueSize;
-
- memcpy(eheader->mData, keyBlob->getData(), keySize);
- memcpy(eheader->mData + keySize, valueBlob->getData(), valueSize);
-
- byteOffset += align4(entrySize);
- }
-
- return OK;
-}
-
-status_t BlobCache::unflatten(void const* buffer, size_t size, int fds[],
- size_t count) {
- // All errors should result in the BlobCache being in an empty state.
- mCacheEntries.clear();
-
- if (count != 0) {
- ALOGE("unflatten: nonzero fd count: %zu", count);
- return BAD_VALUE;
- }
-
- // Read the cache header
- if (size < sizeof(Header)) {
- ALOGE("unflatten: not enough room for cache header");
- return BAD_VALUE;
- }
- const Header* header = reinterpret_cast<const Header*>(buffer);
- if (header->mMagicNumber != blobCacheMagic) {
- ALOGE("unflatten: bad magic number: %d", header->mMagicNumber);
- return BAD_VALUE;
- }
- if (header->mBlobCacheVersion != blobCacheVersion ||
- header->mDeviceVersion != blobCacheDeviceVersion) {
- // We treat version mismatches as an empty cache.
- return OK;
- }
-
- // Read cache entries
- const uint8_t* byteBuffer = reinterpret_cast<const uint8_t*>(buffer);
- off_t byteOffset = align4(sizeof(Header));
- size_t numEntries = header->mNumEntries;
- for (size_t i = 0; i < numEntries; i++) {
- if (byteOffset + sizeof(EntryHeader) > size) {
- mCacheEntries.clear();
- ALOGE("unflatten: not enough room for cache entry headers");
- return BAD_VALUE;
- }
-
- const EntryHeader* eheader = reinterpret_cast<const EntryHeader*>(
- &byteBuffer[byteOffset]);
- size_t keySize = eheader->mKeySize;
- size_t valueSize = eheader->mValueSize;
- size_t entrySize = sizeof(EntryHeader) + keySize + valueSize;
-
- if (byteOffset + entrySize > size) {
- mCacheEntries.clear();
- ALOGE("unflatten: not enough room for cache entry headers");
- return BAD_VALUE;
- }
-
- const uint8_t* data = eheader->mData;
- set(data, keySize, data + keySize, valueSize);
-
- byteOffset += align4(entrySize);
- }
-
- return OK;
-}
-
-long int BlobCache::blob_random() {
-#ifdef _WIN32
- return rand();
-#else
- return nrand48(mRandState);
-#endif
-}
-
-void BlobCache::clean() {
- // Remove a random cache entry until the total cache size gets below half
- // the maximum total cache size.
- while (mTotalSize > mMaxTotalSize / 2) {
- size_t i = size_t(blob_random() % (mCacheEntries.size()));
- const CacheEntry& entry(mCacheEntries[i]);
- mTotalSize -= entry.getKey()->getSize() + entry.getValue()->getSize();
- mCacheEntries.removeAt(i);
- }
-}
-
-bool BlobCache::isCleanable() const {
- return mTotalSize > mMaxTotalSize / 2;
-}
-
-BlobCache::Blob::Blob(const void* data, size_t size, bool copyData):
- mData(copyData ? malloc(size) : data),
- mSize(size),
- mOwnsData(copyData) {
- if (data != NULL && copyData) {
- memcpy(const_cast<void*>(mData), data, size);
- }
-}
-
-BlobCache::Blob::~Blob() {
- if (mOwnsData) {
- free(const_cast<void*>(mData));
- }
-}
-
-bool BlobCache::Blob::operator<(const Blob& rhs) const {
- if (mSize == rhs.mSize) {
- return memcmp(mData, rhs.mData, mSize) < 0;
- } else {
- return mSize < rhs.mSize;
- }
-}
-
-const void* BlobCache::Blob::getData() const {
- return mData;
-}
-
-size_t BlobCache::Blob::getSize() const {
- return mSize;
-}
-
-BlobCache::CacheEntry::CacheEntry() {
-}
-
-BlobCache::CacheEntry::CacheEntry(const sp<Blob>& key, const sp<Blob>& value):
- mKey(key),
- mValue(value) {
-}
-
-BlobCache::CacheEntry::CacheEntry(const CacheEntry& ce):
- mKey(ce.mKey),
- mValue(ce.mValue) {
-}
-
-bool BlobCache::CacheEntry::operator<(const CacheEntry& rhs) const {
- return *mKey < *rhs.mKey;
-}
-
-const BlobCache::CacheEntry& BlobCache::CacheEntry::operator=(const CacheEntry& rhs) {
- mKey = rhs.mKey;
- mValue = rhs.mValue;
- return *this;
-}
-
-sp<BlobCache::Blob> BlobCache::CacheEntry::getKey() const {
- return mKey;
-}
-
-sp<BlobCache::Blob> BlobCache::CacheEntry::getValue() const {
- return mValue;
-}
-
-void BlobCache::CacheEntry::setValue(const sp<Blob>& value) {
- mValue = value;
-}
-
-} // namespace android
generated by cgit v1.1 at 2025-07-03 19:15:09 +0000