/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrResourceCache_DEFINED
#define GrResourceCache_DEFINED
#include "GrConfig.h"
#include "GrTypes.h"
#include "GrTMultiMap.h"
#include "GrBinHashKey.h"
#include "SkMessageBus.h"
#include "SkTInternalLList.h"
class GrCacheable;
class GrResourceCache;
class GrResourceCacheEntry;
class GrResourceKey {
public:
static GrCacheID::Domain ScratchDomain() {
static const GrCacheID::Domain gDomain = GrCacheID::GenerateDomain();
return gDomain;
}
/** Uniquely identifies the GrCacheable subclass in the key to avoid collisions
across resource types. */
typedef uint8_t ResourceType;
/** Flags set by the GrCacheable subclass. */
typedef uint8_t ResourceFlags;
/** Generate a unique ResourceType */
static ResourceType GenerateResourceType();
/** Creates a key for resource */
GrResourceKey(const GrCacheID& id, ResourceType type, ResourceFlags flags) {
this->init(id.getDomain(), id.getKey(), type, flags);
};
GrResourceKey(const GrResourceKey& src) {
fKey = src.fKey;
}
GrResourceKey() {
fKey.reset();
}
void reset(const GrCacheID& id, ResourceType type, ResourceFlags flags) {
this->init(id.getDomain(), id.getKey(), type, flags);
}
uint32_t getHash() const {
return fKey.getHash();
}
bool isScratch() const {
return ScratchDomain() ==
*reinterpret_cast<const GrCacheID::Domain*>(fKey.getData() +
kCacheIDDomainOffset);
}
ResourceType getResourceType() const {
return *reinterpret_cast<const ResourceType*>(fKey.getData() +
kResourceTypeOffset);
}
ResourceFlags getResourceFlags() const {
return *reinterpret_cast<const ResourceFlags*>(fKey.getData() +
kResourceFlagsOffset);
}
bool operator==(const GrResourceKey& other) const { return fKey == other.fKey; }
private:
enum {
kCacheIDKeyOffset = 0,
kCacheIDDomainOffset = kCacheIDKeyOffset + sizeof(GrCacheID::Key),
kResourceTypeOffset = kCacheIDDomainOffset + sizeof(GrCacheID::Domain),
kResourceFlagsOffset = kResourceTypeOffset + sizeof(ResourceType),
kPadOffset = kResourceFlagsOffset + sizeof(ResourceFlags),
kKeySize = SkAlign4(kPadOffset),
kPadSize = kKeySize - kPadOffset
};
void init(const GrCacheID::Domain domain,
const GrCacheID::Key& key,
ResourceType type,
ResourceFlags flags) {
union {
uint8_t fKey8[kKeySize];
uint32_t fKey32[kKeySize / 4];
} keyData;
uint8_t* k = keyData.fKey8;
memcpy(k + kCacheIDKeyOffset, key.fData8, sizeof(GrCacheID::Key));
memcpy(k + kCacheIDDomainOffset, &domain, sizeof(GrCacheID::Domain));
memcpy(k + kResourceTypeOffset, &type, sizeof(ResourceType));
memcpy(k + kResourceFlagsOffset, &flags, sizeof(ResourceFlags));
memset(k + kPadOffset, 0, kPadSize);
fKey.setKeyData(keyData.fKey32);
}
GrBinHashKey<kKeySize> fKey;
};
// The cache listens for these messages to purge junk resources proactively.
struct GrResourceInvalidatedMessage {
GrResourceKey key;
};
///////////////////////////////////////////////////////////////////////////////
class GrResourceCacheEntry {
public:
GrCacheable* resource() const { return fResource; }
const GrResourceKey& key() const { return fKey; }
static const GrResourceKey& GetKey(const GrResourceCacheEntry& e) { return e.key(); }
static uint32_t Hash(const GrResourceKey& key) { return key.getHash(); }
#ifdef SK_DEBUG
void validate() const;
#else
void validate() const {}
#endif
/**
* Update the cached size for this entry and inform the resource cache that
* it has changed. Usually invoked from GrCacheable::didChangeGpuMemorySize,
* not directly from here.
*/
void didChangeResourceSize();
private:
GrResourceCacheEntry(GrResourceCache* resourceCache,
const GrResourceKey& key,
GrCacheable* resource);
~GrResourceCacheEntry();
GrResourceCache* fResourceCache;
GrResourceKey fKey;
GrCacheable* fResource;
size_t fCachedSize;
bool fIsExclusive;
// Linked list for the LRU ordering.
SK_DECLARE_INTERNAL_LLIST_INTERFACE(GrResourceCacheEntry);
friend class GrResourceCache;
};
///////////////////////////////////////////////////////////////////////////////
/**
* Cache of GrCacheable objects.
*
* These have a corresponding GrResourceKey, built from 128bits identifying the
* resource. Multiple resources can map to same GrResourceKey.
*
* The cache stores the entries in a double-linked list, which is its LRU.
* When an entry is "locked" (i.e. given to the caller), it is moved to the
* head of the list. If/when we must purge some of the entries, we walk the
* list backwards from the tail, since those are the least recently used.
*
* For fast searches, we maintain a hash map based on the GrResourceKey.
*
* It is a goal to make the GrResourceCache the central repository and bookkeeper
* of all resources. It should replace the linked list of GrGpuObjects that
* GrGpu uses to call abandon/release.
*/
class GrResourceCache {
public:
GrResourceCache(int maxCount, size_t maxBytes);
~GrResourceCache();
/**
* Return the current resource cache limits.
*
* @param maxResource If non-null, returns maximum number of resources
* that can be held in the cache.
* @param maxBytes If non-null, returns maximum number of bytes of
* gpu memory that can be held in the cache.
*/
void getLimits(int* maxResources, size_t* maxBytes) const;
/**
* Specify the resource cache limits. If the current cache exceeds either
* of these, it will be purged (LRU) to keep the cache within these limits.
*
* @param maxResources The maximum number of resources that can be held in
* the cache.
* @param maxBytes The maximum number of bytes of resource memory that
* can be held in the cache.
*/
void setLimits(int maxResources, size_t maxResourceBytes);
/**
* The callback function used by the cache when it is still over budget
* after a purge. The passed in 'data' is the same 'data' handed to
* setOverbudgetCallback. The callback returns true if some resources
* have been freed.
*/
typedef bool (*PFOverbudgetCB)(void* data);
/**
* Set the callback the cache should use when it is still over budget
* after a purge. The 'data' provided here will be passed back to the
* callback. Note that the cache will attempt to purge any resources newly
* freed by the callback.
*/
void setOverbudgetCallback(PFOverbudgetCB overbudgetCB, void* data) {
fOverbudgetCB = overbudgetCB;
fOverbudgetData = data;
}
/**
* Returns the number of bytes consumed by cached resources.
*/
size_t getCachedResourceBytes() const { return fEntryBytes; }
/**
* Returns the number of cached resources.
*/
int getCachedResourceCount() const { return fEntryCount; }
// For a found or added resource to be completely exclusive to the caller
// both the kNoOtherOwners and kHide flags need to be specified
enum OwnershipFlags {
kNoOtherOwners_OwnershipFlag = 0x1, // found/added resource has no other owners
kHide_OwnershipFlag = 0x2 // found/added resource is hidden from future 'find's
};
/**
* Search for an entry with the same Key. If found, return it.
* If not found, return null.
* If ownershipFlags includes kNoOtherOwners and a resource is returned
* then that resource has no other refs to it.
* If ownershipFlags includes kHide and a resource is returned then that
* resource will not be returned from future 'find' calls until it is
* 'freed' (and recycled) or makeNonExclusive is called.
* For a resource to be completely exclusive to a caller both kNoOtherOwners
* and kHide must be specified.
*/
GrCacheable* find(const GrResourceKey& key,
uint32_t ownershipFlags = 0);
/**
* Add the new resource to the cache (by creating a new cache entry based
* on the provided key and resource).
*
* Ownership of the resource is transferred to the resource cache,
* which will unref() it when it is purged or deleted.
*
* If ownershipFlags includes kHide, subsequent calls to 'find' will not
* return 'resource' until it is 'freed' (and recycled) or makeNonExclusive
* is called.
*/
void addResource(const GrResourceKey& key,
GrCacheable* resource,
uint32_t ownershipFlags = 0);
/**
* Determines if the cache contains an entry matching a key. If a matching
* entry exists but was detached then it will not be found.
*/
bool hasKey(const GrResourceKey& key) const { return NULL != fCache.find(key); }
/**
* Hide 'entry' so that future searches will not find it. Such
* hidden entries will not be purged. The entry still counts against
* the cache's budget and should be made non-exclusive when exclusive access
* is no longer needed.
*/
void makeExclusive(GrResourceCacheEntry* entry);
/**
* Restore 'entry' so that it can be found by future searches. 'entry'
* will also be purgeable (provided its lock count is now 0.)
*/
void makeNonExclusive(GrResourceCacheEntry* entry);
/**
* Notify the cache that the size of a resource has changed.
*/
void didIncreaseResourceSize(const GrResourceCacheEntry*, size_t amountInc);
void didDecreaseResourceSize(const GrResourceCacheEntry*, size_t amountDec);
/**
* Remove a resource from the cache and delete it!
*/
void deleteResource(GrResourceCacheEntry* entry);
/**
* Removes every resource in the cache that isn't locked.
*/
void purgeAllUnlocked();
/**
* Allow cache to purge unused resources to obey resource limitations
* Note: this entry point will be hidden (again) once totally ref-driven
* cache maintenance is implemented. Note that the overbudget callback
* will be called if the initial purge doesn't get the cache under
* its budget.
*
* extraCount and extraBytes are added to the current resource allocation
* to make sure enough room is available for future additions (e.g,
* 10MB across 10 textures is about to be added).
*/
void purgeAsNeeded(int extraCount = 0, size_t extraBytes = 0);
#ifdef SK_DEBUG
void validate() const;
#else
void validate() const {}
#endif
#if GR_CACHE_STATS
void printStats();
#endif
private:
enum BudgetBehaviors {
kAccountFor_BudgetBehavior,
kIgnore_BudgetBehavior
};
void internalDetach(GrResourceCacheEntry*, BudgetBehaviors behavior = kAccountFor_BudgetBehavior);
void attachToHead(GrResourceCacheEntry*, BudgetBehaviors behavior = kAccountFor_BudgetBehavior);
void removeInvalidResource(GrResourceCacheEntry* entry);
GrTMultiMap<GrResourceCacheEntry, GrResourceKey> fCache;
// We're an internal doubly linked list
typedef SkTInternalLList<GrResourceCacheEntry> EntryList;
EntryList fList;
#ifdef SK_DEBUG
// These objects cannot be returned by a search
EntryList fExclusiveList;
#endif
// our budget, used in purgeAsNeeded()
int fMaxCount;
size_t fMaxBytes;
// our current stats, related to our budget
#if GR_CACHE_STATS
int fHighWaterEntryCount;
size_t fHighWaterEntryBytes;
int fHighWaterClientDetachedCount;
size_t fHighWaterClientDetachedBytes;
#endif
int fEntryCount;
size_t fEntryBytes;
int fClientDetachedCount;
size_t fClientDetachedBytes;
// prevents recursive purging
bool fPurging;
PFOverbudgetCB fOverbudgetCB;
void* fOverbudgetData;
void internalPurge(int extraCount, size_t extraBytes);
// Listen for messages that a resource has been invalidated and purge cached junk proactively.
SkMessageBus<GrResourceInvalidatedMessage>::Inbox fInvalidationInbox;
void purgeInvalidated();
#ifdef SK_DEBUG
static size_t countBytes(const SkTInternalLList<GrResourceCacheEntry>& list);
#endif
};
///////////////////////////////////////////////////////////////////////////////
#ifdef SK_DEBUG
class GrAutoResourceCacheValidate {
public:
GrAutoResourceCacheValidate(GrResourceCache* cache) : fCache(cache) {
cache->validate();
}
~GrAutoResourceCacheValidate() {
fCache->validate();
}
private:
GrResourceCache* fCache;
};
#else
class GrAutoResourceCacheValidate {
public:
GrAutoResourceCacheValidate(GrResourceCache*) {}
};
#endif
#endif