skia2/include/gpu/GrResourceKey.h
mtklein d9dd428211 Modernize and trim down SkOnce.
The API and implementation are very much simplified.
You may not want to bother reading the diff.

As is our trend, SkOnce now uses <atomic> directly.

Member initialization means we don't need SK_DECLARE_STATIC_ONCE.
SkSpinlock already works this same way.

All uses of the old API taking an external bool* and Lock* were pessimal,
so I have not carried this sort of API forward.  It's simpler, faster,
and more space-efficient to always use this single SkOnce class interface.

SkOnce weighs 2 bytes: a done bool and an SkSpinlock, also a bool internally.
This API refactoring opens up the opportunity to fuse those into a single
three-state byte if we'd like.

No public API changes.
TBR=reed@google.com

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1894893002

Review URL: https://codereview.chromium.org/1894893002
2016-04-18 08:09:11 -07:00

324 lines
11 KiB
C++

/*
* Copyright 2014 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrResourceKey_DEFINED
#define GrResourceKey_DEFINED
#include "../private/SkTemplates.h"
#include "GrTypes.h"
#include "SkData.h"
#include "../private/SkOnce.h"
uint32_t GrResourceKeyHash(const uint32_t* data, size_t size);
/**
* Base class for all GrGpuResource cache keys. There are two types of cache keys. Refer to the
* comments for each key type below.
*/
class GrResourceKey {
public:
uint32_t hash() const {
this->validate();
return fKey[kHash_MetaDataIdx];
}
size_t size() const {
this->validate();
SkASSERT(this->isValid());
return this->internalSize();
}
protected:
static const uint32_t kInvalidDomain = 0;
GrResourceKey() { this->reset(); }
/** Reset to an invalid key. */
void reset() {
GR_STATIC_ASSERT((uint16_t)kInvalidDomain == kInvalidDomain);
fKey.reset(kMetaDataCnt);
fKey[kHash_MetaDataIdx] = 0;
fKey[kDomainAndSize_MetaDataIdx] = kInvalidDomain;
}
bool operator==(const GrResourceKey& that) const {
return this->hash() == that.hash() &&
0 == memcmp(&fKey[kHash_MetaDataIdx + 1],
&that.fKey[kHash_MetaDataIdx + 1],
this->internalSize() - sizeof(uint32_t));
}
GrResourceKey& operator=(const GrResourceKey& that) {
SkASSERT(that.isValid());
if (this != &that) {
size_t bytes = that.size();
SkASSERT(SkIsAlign4(bytes));
fKey.reset(SkToInt(bytes / sizeof(uint32_t)));
memcpy(fKey.get(), that.fKey.get(), bytes);
this->validate();
}
return *this;
}
bool isValid() const { return kInvalidDomain != this->domain(); }
uint32_t domain() const { return fKey[kDomainAndSize_MetaDataIdx] & 0xffff; }
/** size of the key data, excluding meta-data (hash, domain, etc). */
size_t dataSize() const { return this->size() - 4 * kMetaDataCnt; }
/** ptr to the key data, excluding meta-data (hash, domain, etc). */
const uint32_t* data() const {
this->validate();
return &fKey[kMetaDataCnt];
}
/** Used to initialize a key. */
class Builder {
public:
Builder(GrResourceKey* key, uint32_t domain, int data32Count) : fKey(key) {
SkASSERT(data32Count >= 0);
SkASSERT(domain != kInvalidDomain);
key->fKey.reset(kMetaDataCnt + data32Count);
int size = (data32Count + kMetaDataCnt) * sizeof(uint32_t);
SkASSERT(SkToU16(size) == size);
SkASSERT(SkToU16(domain) == domain);
key->fKey[kDomainAndSize_MetaDataIdx] = domain | (size << 16);
}
~Builder() { this->finish(); }
void finish() {
if (NULL == fKey) {
return;
}
GR_STATIC_ASSERT(0 == kHash_MetaDataIdx);
uint32_t* hash = &fKey->fKey[kHash_MetaDataIdx];
*hash = GrResourceKeyHash(hash + 1, fKey->internalSize() - sizeof(uint32_t));
fKey->validate();
fKey = NULL;
}
uint32_t& operator[](int dataIdx) {
SkASSERT(fKey);
SkDEBUGCODE(size_t dataCount = fKey->internalSize() / sizeof(uint32_t) - kMetaDataCnt;)
SkASSERT(SkToU32(dataIdx) < dataCount);
return fKey->fKey[kMetaDataCnt + dataIdx];
}
private:
GrResourceKey* fKey;
};
private:
enum MetaDataIdx {
kHash_MetaDataIdx,
// The key domain and size are packed into a single uint32_t.
kDomainAndSize_MetaDataIdx,
kLastMetaDataIdx = kDomainAndSize_MetaDataIdx
};
static const uint32_t kMetaDataCnt = kLastMetaDataIdx + 1;
size_t internalSize() const {
return fKey[kDomainAndSize_MetaDataIdx] >> 16;
}
void validate() const {
SkASSERT(fKey[kHash_MetaDataIdx] ==
GrResourceKeyHash(&fKey[kHash_MetaDataIdx] + 1,
this->internalSize() - sizeof(uint32_t)));
SkASSERT(SkIsAlign4(this->internalSize()));
}
friend class TestResource; // For unit test to access kMetaDataCnt.
// bmp textures require 5 uint32_t values.
SkAutoSTMalloc<kMetaDataCnt + 5, uint32_t> fKey;
};
/**
* A key used for scratch resources. There are three important rules about scratch keys:
* * Multiple resources can share the same scratch key. Therefore resources assigned the same
* scratch key should be interchangeable with respect to the code that uses them.
* * A resource can have at most one scratch key and it is set at resource creation by the
* resource itself.
* * When a scratch resource is ref'ed it will not be returned from the
* cache for a subsequent cache request until all refs are released. This facilitates using
* a scratch key for multiple render-to-texture scenarios. An example is a separable blur:
*
* GrTexture* texture[2];
* texture[0] = get_scratch_texture(scratchKey);
* texture[1] = get_scratch_texture(scratchKey); // texture[0] is already owned so we will get a
* // different one for texture[1]
* draw_mask(texture[0], path); // draws path mask to texture[0]
* blur_x(texture[0], texture[1]); // blurs texture[0] in y and stores result in texture[1]
* blur_y(texture[1], texture[0]); // blurs texture[1] in y and stores result in texture[0]
* texture[1]->unref(); // texture 1 can now be recycled for the next request with scratchKey
* consume_blur(texture[0]);
* texture[0]->unref(); // texture 0 can now be recycled for the next request with scratchKey
*/
class GrScratchKey : public GrResourceKey {
private:
typedef GrResourceKey INHERITED;
public:
/** Uniquely identifies the type of resource that is cached as scratch. */
typedef uint32_t ResourceType;
/** Generate a unique ResourceType. */
static ResourceType GenerateResourceType();
/** Creates an invalid scratch key. It must be initialized using a Builder object before use. */
GrScratchKey() {}
GrScratchKey(const GrScratchKey& that) { *this = that; }
/** reset() returns the key to the invalid state. */
using INHERITED::reset;
using INHERITED::isValid;
ResourceType resourceType() const { return this->domain(); }
GrScratchKey& operator=(const GrScratchKey& that) {
this->INHERITED::operator=(that);
return *this;
}
bool operator==(const GrScratchKey& that) const {
return this->INHERITED::operator==(that);
}
bool operator!=(const GrScratchKey& that) const { return !(*this == that); }
class Builder : public INHERITED::Builder {
public:
Builder(GrScratchKey* key, ResourceType type, int data32Count)
: INHERITED::Builder(key, type, data32Count) {}
};
};
/**
* A key that allows for exclusive use of a resource for a use case (AKA "domain"). There are three
* rules governing the use of unique keys:
* * Only one resource can have a given unique key at a time. Hence, "unique".
* * A resource can have at most one unique key at a time.
* * Unlike scratch keys, multiple requests for a unique key will return the same
* resource even if the resource already has refs.
* This key type allows a code path to create cached resources for which it is the exclusive user.
* The code path creates a domain which it sets on its keys. This guarantees that there are no
* cross-domain collisions.
*
* Unique keys preempt scratch keys. While a resource has a unique key it is inaccessible via its
* scratch key. It can become scratch again if the unique key is removed.
*/
class GrUniqueKey : public GrResourceKey {
private:
typedef GrResourceKey INHERITED;
public:
typedef uint32_t Domain;
/** Generate a Domain for unique keys. */
static Domain GenerateDomain();
/** Creates an invalid unique key. It must be initialized using a Builder object before use. */
GrUniqueKey() {}
GrUniqueKey(const GrUniqueKey& that) { *this = that; }
/** reset() returns the key to the invalid state. */
using INHERITED::reset;
using INHERITED::isValid;
GrUniqueKey& operator=(const GrUniqueKey& that) {
this->INHERITED::operator=(that);
this->setCustomData(that.getCustomData());
return *this;
}
bool operator==(const GrUniqueKey& that) const {
return this->INHERITED::operator==(that);
}
bool operator!=(const GrUniqueKey& that) const { return !(*this == that); }
void setCustomData(const SkData* data) {
SkSafeRef(data);
fData.reset(data);
}
const SkData* getCustomData() const {
return fData.get();
}
class Builder : public INHERITED::Builder {
public:
Builder(GrUniqueKey* key, Domain domain, int data32Count)
: INHERITED::Builder(key, domain, data32Count) {}
/** Used to build a key that wraps another key and adds additional data. */
Builder(GrUniqueKey* key, const GrUniqueKey& innerKey, Domain domain,
int extraData32Cnt)
: INHERITED::Builder(key, domain, Data32CntForInnerKey(innerKey) + extraData32Cnt) {
SkASSERT(&innerKey != key);
// add the inner key to the end of the key so that op[] can be indexed normally.
uint32_t* innerKeyData = &this->operator[](extraData32Cnt);
const uint32_t* srcData = innerKey.data();
(*innerKeyData++) = innerKey.domain();
memcpy(innerKeyData, srcData, innerKey.dataSize());
}
private:
static int Data32CntForInnerKey(const GrUniqueKey& innerKey) {
// key data + domain
return SkToInt((innerKey.dataSize() >> 2) + 1);
}
};
private:
SkAutoTUnref<const SkData> fData;
};
/**
* It is common to need a frequently reused GrUniqueKey where the only requirement is that the key
* is unique. These macros create such a key in a thread safe manner so the key can be truly global
* and only constructed once.
*/
/** Place outside of function/class definitions. */
#define GR_DECLARE_STATIC_UNIQUE_KEY(name) static SkOnce name##_once
/** Place inside function where the key is used. */
#define GR_DEFINE_STATIC_UNIQUE_KEY(name) \
static SkAlignedSTStorage<1, GrUniqueKey> name##_storage; \
name##_once(gr_init_static_unique_key_once, &name##_storage); \
static const GrUniqueKey& name = *reinterpret_cast<GrUniqueKey*>(name##_storage.get());
static inline void gr_init_static_unique_key_once(SkAlignedSTStorage<1,GrUniqueKey>* keyStorage) {
GrUniqueKey* key = new (keyStorage->get()) GrUniqueKey;
GrUniqueKey::Builder builder(key, GrUniqueKey::GenerateDomain(), 0);
}
// The cache listens for these messages to purge junk resources proactively.
class GrUniqueKeyInvalidatedMessage {
public:
explicit GrUniqueKeyInvalidatedMessage(const GrUniqueKey& key) : fKey(key) {}
GrUniqueKeyInvalidatedMessage(const GrUniqueKeyInvalidatedMessage& that) : fKey(that.fKey) {}
GrUniqueKeyInvalidatedMessage& operator=(const GrUniqueKeyInvalidatedMessage& that) {
fKey = that.fKey;
return *this;
}
const GrUniqueKey& key() const { return fKey; }
private:
GrUniqueKey fKey;
};
#endif