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Enable fetching of stale items

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It is now possible to specify that a cache item should be returned
if it exists, even if it is stale.
This commit is contained in:
Johan Wikman 2016-11-22 10:57:23 +02:00
parent 15a03375c2
commit 79a03049a1
5 changed files with 30 additions and 7 deletions
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2
server/modules/filter/cache/cache.c vendored
View File

@ -1087,7 +1087,7 @@ static bool route_using_cache(CACHE_SESSION_DATA *csdata,
if (result == CACHE_RESULT_OK)
{
result = csdata->api->getValue(csdata->storage, csdata->key, value);
result = csdata->api->getValue(csdata->storage, csdata->key, CACHE_FLAGS_NONE, value);
}
else
{

11
server/modules/filter/cache/cache_storage_api.h vendored
View File

@ -26,10 +26,17 @@ typedef enum cache_result
{
CACHE_RESULT_OK,
CACHE_RESULT_NOT_FOUND,
CACHE_RESULT_STALE,
CACHE_RESULT_OUT_OF_RESOURCES,
CACHE_RESULT_ERROR
} cache_result_t;
typedef enum cache_flags
{
CACHE_FLAGS_NONE = 0x00,
CACHE_FLAGS_INCLUDE_STALE = 0x01,
} cache_flags_t;
typedef void* CACHE_STORAGE;
enum
@ -88,14 +95,18 @@ typedef struct cache_storage_api
*
* @param storage Pointer to a CACHE_STORAGE.
* @param key A key generated with getKey.
* @param flags Mask of cache_flags_t values.
* @param result Pointer to variable that after a successful return will
* point to a GWBUF.
* @return CACHE_RESULT_OK if item was found,
* CACHE_RESULT_STALE if CACHE_FLAGS_INCLUDE_STALE was specified in
* flags and the item was found but stale,
* CACHE_RESULT_NOT_FOUND if item was not found (which may be because
* the ttl was reached), or some other error code.
*/
cache_result_t (*getValue)(CACHE_STORAGE* storage,
const char* key,
uint32_t flags,
GWBUF** result);
/**

15
server/modules/filter/cache/storage/storage_rocksdb/rocksdbstorage.cc vendored
View File

@ -403,7 +403,7 @@ cache_result_t RocksDBStorage::getKey(const char* zDefaultDB, const GWBUF* pQuer
return CACHE_RESULT_OK;
}
cache_result_t RocksDBStorage::getValue(const char* pKey, GWBUF** ppResult)
cache_result_t RocksDBStorage::getValue(const char* pKey, uint32_t flags, GWBUF** ppResult)
{
// Use the root DB so that we get the value *with* the timestamp at the end.
rocksdb::DB* pDb = m_sDb->GetRootDB();
@ -419,7 +419,9 @@ cache_result_t RocksDBStorage::getValue(const char* pKey, GWBUF** ppResult)
case rocksdb::Status::kOk:
if (value.length() >= RocksDBInternals::TS_LENGTH)
{
if (!RocksDBInternals::IsStale(value, m_ttl, rocksdb::Env::Default()))
bool isStale = RocksDBInternals::IsStale(value, m_ttl, rocksdb::Env::Default());
if (!isStale || ((flags & CACHE_FLAGS_INCLUDE_STALE) != 0))
{
size_t length = value.length() - RocksDBInternals::TS_LENGTH;
@ -429,7 +431,14 @@ cache_result_t RocksDBStorage::getValue(const char* pKey, GWBUF** ppResult)
{
memcpy(GWBUF_DATA(*ppResult), value.data(), length);
result = CACHE_RESULT_OK;
if (isStale)
{
result = CACHE_RESULT_STALE;
}
else
{
result = CACHE_RESULT_OK;
}
}
}
else

2
server/modules/filter/cache/storage/storage_rocksdb/rocksdbstorage.h vendored
View File

@ -30,7 +30,7 @@ public:
~RocksDBStorage();
cache_result_t getKey(const char* zDefaultDB, const GWBUF* pQuery, char* pKey);
cache_result_t getValue(const char* pKey, GWBUF** ppResult);
cache_result_t getValue(const char* pKey, uint32_t flags, GWBUF** ppResult);
cache_result_t putValue(const char* pKey, const GWBUF* pValue);
private:

7
server/modules/filter/cache/storage/storage_rocksdb/storage_rocksdb.cc vendored
View File

@ -86,7 +86,10 @@ cache_result_t getKey(CACHE_STORAGE* pStorage,
return result;
}
cache_result_t getValue(CACHE_STORAGE* pStorage, const char* pKey, GWBUF** ppResult)
cache_result_t getValue(CACHE_STORAGE* pStorage,
const char* pKey,
uint32_t flags,
GWBUF** ppResult)
{
ss_dassert(pStorage);
ss_dassert(pKey);
@ -96,7 +99,7 @@ cache_result_t getValue(CACHE_STORAGE* pStorage, const char* pKey, GWBUF** ppRes
try
{
result = reinterpret_cast<RocksDBStorage*>(pStorage)->getValue(pKey, ppResult);
result = reinterpret_cast<RocksDBStorage*>(pStorage)->getValue(pKey, flags, ppResult);
}
catch (const std::bad_alloc&)
{