AuroraMiddleware/skia2
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Remove unused PackBits methods and fix length checks

Browse Source 
Also a bit of general cleanup.

BUG=chromium:486944

Review URL: https://codereview.chromium.org/1152163004
This commit is contained in:
jschuh 2015-06-04 15:10:37 -07:00 committed by Commit bot
parent 821e10ed41
commit 699b852e48
4 changed files with 46 additions and 436 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
include/core/SkPackBits.h
View File

@ -14,66 +14,33 @@
class SkPackBits {
public:
/** Given the number of 16bit values that will be passed to Pack16,
returns the worst-case size needed for the dst[] buffer.
*/
static size_t ComputeMaxSize16(int count);
/** Given the number of 8bit values that will be passed to Pack8,
returns the worst-case size needed for the dst[] buffer.
*/
static size_t ComputeMaxSize8(int count);
/** Write the src array into a packed format. The packing process may end
up writing more bytes than it read, so dst[] must be large enough.
@param src Input array of 16bit values
@param count Number of entries in src[]
@param dst Buffer (allocated by caller) to write the packed data
into
@return the number of bytes written to dst[]
*/
static size_t Pack16(const uint16_t src[], int count, uint8_t dst[]);
/** Write the src array into a packed format. The packing process may end
up writing more bytes than it read, so dst[] must be large enough.
@param src Input array of 8bit values
@param count Number of entries in src[]
@param srcSize Number of entries in src[]
@param dst Buffer (allocated by caller) to write the packed data
into
@param dstSize Number of bytes in the output buffer.
@return the number of bytes written to dst[]
*/
static size_t Pack8(const uint8_t src[], int count, uint8_t dst[]);
/** Unpack the data in src[], and expand it into dst[]. The src[] data was
written by a previous call to Pack16.
@param src Input data to unpack, previously created by Pack16.
@param srcSize Number of bytes of src to unpack
@param dst Buffer (allocated by caller) to expand the src[] into.
@return the number of dst elements (not bytes) written into dst.
*/
static int Unpack16(const uint8_t src[], size_t srcSize, uint16_t dst[]);
static size_t Pack8(const uint8_t src[], size_t srcSize, uint8_t dst[],
size_t dstSize);
/** Unpack the data in src[], and expand it into dst[]. The src[] data was
written by a previous call to Pack8.
@param src Input data to unpack, previously created by Pack8.
@param srcSize Number of bytes of src to unpack
@param dst Buffer (allocated by caller) to expand the src[] into.
@param dstSize Number of bytes in the output buffer.
@return the number of bytes written into dst.
*/
static int Unpack8(const uint8_t src[], size_t srcSize, uint8_t dst[]);
/** Unpack the data from src[], skip the first dstSkip bytes, then write
dstWrite bytes into dst[]. The src[] data was written by a previous
call to Pack8. Return the number of bytes actually writtten into dst[]
@param src Input data to unpack, previously created by Pack8.
@param dst Buffer (allocated by caller) to expand the src[] into.
@param dstSkip Number of bytes of unpacked src to skip before writing
into dst
@param dstWrite Number of bytes of unpacked src to write into dst (after
skipping dstSkip bytes)
*/
static void Unpack8(uint8_t dst[], size_t dstSkip, size_t dstWrite,
const uint8_t src[]);
static int Unpack8(const uint8_t src[], size_t srcSize, uint8_t dst[],
size_t dstSize);
};
#endif

354
src/core/SkPackBits.cpp
View File

@ -1,4 +1,3 @@
/*
* Copyright 2011 Google Inc.
*
@ -7,150 +6,14 @@
*/
#include "SkPackBits.h"
#define GATHER_STATSx
static inline void small_memcpy(void* SK_RESTRICT dst,
const void* SK_RESTRICT src, size_t n) {
SkASSERT(n > 0 && n <= 15);
uint8_t* d = (uint8_t*)dst;
const uint8_t* s = (const uint8_t*)src;
switch (n) {
case 15: *d++ = *s++;
case 14: *d++ = *s++;
case 13: *d++ = *s++;
case 12: *d++ = *s++;
case 11: *d++ = *s++;
case 10: *d++ = *s++;
case 9: *d++ = *s++;
case 8: *d++ = *s++;
case 7: *d++ = *s++;
case 6: *d++ = *s++;
case 5: *d++ = *s++;
case 4: *d++ = *s++;
case 3: *d++ = *s++;
case 2: *d++ = *s++;
case 1: *d++ = *s++;
case 0: break;
}
}
static inline void small_memset(void* dst, uint8_t value, size_t n) {
SkASSERT(n > 0 && n <= 15);
uint8_t* d = (uint8_t*)dst;
switch (n) {
case 15: *d++ = value;
case 14: *d++ = value;
case 13: *d++ = value;
case 12: *d++ = value;
case 11: *d++ = value;
case 10: *d++ = value;
case 9: *d++ = value;
case 8: *d++ = value;
case 7: *d++ = value;
case 6: *d++ = value;
case 5: *d++ = value;
case 4: *d++ = value;
case 3: *d++ = value;
case 2: *d++ = value;
case 1: *d++ = value;
case 0: break;
}
}
// can we do better for small counts with our own inlined memcpy/memset?
#define PB_MEMSET(addr, value, count) \
do { \
if ((count) > 15) { \
memset(addr, value, count); \
} else { \
small_memset(addr, value, count); \
} \
} while (0)
#define PB_MEMCPY(dst, src, count) \
do { \
if ((count) > 15) { \
memcpy(dst, src, count); \
} else { \
small_memcpy(dst, src, count); \
} \
} while (0)
///////////////////////////////////////////////////////////////////////////////
#ifdef GATHER_STATS
static int gMemSetBuckets[129];
static int gMemCpyBuckets[129];
static int gCounter;
static void register_memset_count(int n) {
SkASSERT((unsigned)n <= 128);
gMemSetBuckets[n] += 1;
gCounter += 1;
if ((gCounter & 0xFF) == 0) {
SkDebugf("----- packbits memset stats: ");
for (size_t i = 0; i < SK_ARRAY_COUNT(gMemSetBuckets); i++) {
if (gMemSetBuckets[i]) {
SkDebugf(" %d:%d", i, gMemSetBuckets[i]);
}
}
}
}
static void register_memcpy_count(int n) {
SkASSERT((unsigned)n <= 128);
gMemCpyBuckets[n] += 1;
gCounter += 1;
if ((gCounter & 0x1FF) == 0) {
SkDebugf("----- packbits memcpy stats: ");
for (size_t i = 0; i < SK_ARRAY_COUNT(gMemCpyBuckets); i++) {
if (gMemCpyBuckets[i]) {
SkDebugf(" %d:%d", i, gMemCpyBuckets[i]);
}
}
}
}
#else
#define register_memset_count(n)
#define register_memcpy_count(n)
#endif
///////////////////////////////////////////////////////////////////////////////
size_t SkPackBits::ComputeMaxSize16(int count) {
// worst case is the number of 16bit values (times 2) +
// 1 byte per (up to) 128 entries.
return ((count + 127) >> 7) + (count << 1);
}
size_t SkPackBits::ComputeMaxSize8(int count) {
// worst case is the number of 8bit values + 1 byte per (up to) 128 entries.
return ((count + 127) >> 7) + count;
}
static uint8_t* flush_same16(uint8_t dst[], uint16_t value, int count) {
static uint8_t* flush_same8(uint8_t dst[], uint8_t value, size_t count) {
while (count > 0) {
int n = count;
if (n > 128) {
n = 128;
}
*dst++ = (uint8_t)(n - 1);
*dst++ = (uint8_t)(value >> 8);
*dst++ = (uint8_t)value;
count -= n;
}
return dst;
}
static uint8_t* flush_same8(uint8_t dst[], uint8_t value, int count) {
while (count > 0) {
int n = count;
if (n > 128) {
n = 128;
}
int n = count > 128 ? 128 : count;
*dst++ = (uint8_t)(n - 1);
*dst++ = (uint8_t)value;
count -= n;
@ -158,31 +21,12 @@ static uint8_t* flush_same8(uint8_t dst[], uint8_t value, int count) {
return dst;
}
static uint8_t* flush_diff16(uint8_t* SK_RESTRICT dst,
const uint16_t* SK_RESTRICT src, int count) {
while (count > 0) {
int n = count;
if (n > 128) {
n = 128;
}
*dst++ = (uint8_t)(n + 127);
PB_MEMCPY(dst, src, n * sizeof(uint16_t));
src += n;
dst += n * sizeof(uint16_t);
count -= n;
}
return dst;
}
static uint8_t* flush_diff8(uint8_t* SK_RESTRICT dst,
const uint8_t* SK_RESTRICT src, int count) {
const uint8_t* SK_RESTRICT src, size_t count) {
while (count > 0) {
int n = count;
if (n > 128) {
n = 128;
}
int n = count > 128 ? 128 : count;
*dst++ = (uint8_t)(n + 127);
PB_MEMCPY(dst, src, n);
memcpy(dst, src, n);
src += n;
dst += n;
count -= n;
@ -190,64 +34,20 @@ static uint8_t* flush_diff8(uint8_t* SK_RESTRICT dst,
return dst;
}
size_t SkPackBits::Pack16(const uint16_t* SK_RESTRICT src, int count,
uint8_t* SK_RESTRICT dst) {
uint8_t* origDst = dst;
const uint16_t* stop = src + count;
for (;;) {
count = SkToInt(stop - src);
SkASSERT(count >= 0);
if (count == 0) {
return dst - origDst;
}
if (1 == count) {
*dst++ = 0;
*dst++ = (uint8_t)(*src >> 8);
*dst++ = (uint8_t)*src;
return dst - origDst;
}
unsigned value = *src;
const uint16_t* s = src + 1;
if (*s == value) { // accumulate same values...
do {
s++;
if (s == stop) {
break;
}
} while (*s == value);
dst = flush_same16(dst, value, SkToInt(s - src));
} else { // accumulate diff values...
do {
if (++s == stop) {
goto FLUSH_DIFF;
}
} while (*s != s[-1]);
s -= 1; // back up so we don't grab one of the "same" values that follow
FLUSH_DIFF:
dst = flush_diff16(dst, src, SkToInt(s - src));
}
src = s;
size_t SkPackBits::Pack8(const uint8_t* SK_RESTRICT src, size_t srcSize,
uint8_t* SK_RESTRICT dst, size_t dstSize) {
if (dstSize < ComputeMaxSize8(srcSize)) {
return 0;
}
}
size_t SkPackBits::Pack8(const uint8_t* SK_RESTRICT src, int count,
uint8_t* SK_RESTRICT dst) {
uint8_t* origDst = dst;
const uint8_t* stop = src + count;
uint8_t* const origDst = dst;
const uint8_t* stop = src + srcSize;
for (;;) {
count = SkToInt(stop - src);
SkASSERT(count >= 0);
if (count == 0) {
return dst - origDst;
}
for (intptr_t count = stop - src; count > 0; count = stop - src) {
if (1 == count) {
*dst++ = 0;
*dst++ = *src;
return dst - origDst;
break;
}
unsigned value = *src;
@ -275,137 +75,35 @@ size_t SkPackBits::Pack8(const uint8_t* SK_RESTRICT src, int count,
}
src = s;
}
return dst - origDst;
}
#include "SkUtils.h"
int SkPackBits::Unpack16(const uint8_t* SK_RESTRICT src, size_t srcSize,
uint16_t* SK_RESTRICT dst) {
uint16_t* origDst = dst;
const uint8_t* stop = src + srcSize;
while (src < stop) {
unsigned n = *src++;
if (n <= 127) { // repeat count (n + 1)
n += 1;
sk_memset16(dst, (src[0] << 8) | src[1], n);
src += 2;
} else { // same count (n - 127)
n -= 127;
PB_MEMCPY(dst, src, n * sizeof(uint16_t));
src += n * sizeof(uint16_t);
}
dst += n;
}
SkASSERT(src == stop);
return SkToInt(dst - origDst);
}
int SkPackBits::Unpack8(const uint8_t* SK_RESTRICT src, size_t srcSize,
uint8_t* SK_RESTRICT dst) {
uint8_t* origDst = dst;
uint8_t* SK_RESTRICT dst, size_t dstSize) {
uint8_t* const origDst = dst;
uint8_t* const endDst = dst + dstSize;
const uint8_t* stop = src + srcSize;
while (src < stop) {
unsigned n = *src++;
if (n <= 127) { // repeat count (n + 1)
n += 1;
PB_MEMSET(dst, *src++, n);
if (dst >(endDst - n)) {
return 0;
}
memset(dst, *src++, n);
} else { // same count (n - 127)
n -= 127;
PB_MEMCPY(dst, src, n);
if (dst > (endDst - n)) {
return 0;
}
memcpy(dst, src, n);
src += n;
}
dst += n;
}
SkASSERT(src == stop);
SkASSERT(src <= stop);
return SkToInt(dst - origDst);
}
enum UnpackState {
CLEAN_STATE,
REPEAT_BYTE_STATE,
COPY_SRC_STATE
};
void SkPackBits::Unpack8(uint8_t* SK_RESTRICT dst, size_t dstSkip,
size_t dstWrite, const uint8_t* SK_RESTRICT src) {
if (dstWrite == 0) {
return;
}
UnpackState state = CLEAN_STATE;
size_t stateCount = 0;
// state 1: do the skip-loop
while (dstSkip > 0) {
size_t n = *src++;
if (n <= 127) { // repeat count (n + 1)
n += 1;
if (n > dstSkip) {
state = REPEAT_BYTE_STATE;
stateCount = n - dstSkip;
n = dstSkip;
// we don't increment src here, since its needed in stage 2
} else {
src++; // skip the src byte
}
} else { // same count (n - 127)
n -= 127;
if (n > dstSkip) {
state = COPY_SRC_STATE;
stateCount = n - dstSkip;
n = dstSkip;
}
src += n;
}
dstSkip -= n;
}
// stage 2: perform any catchup from the skip-stage
if (stateCount > dstWrite) {
stateCount = dstWrite;
}
switch (state) {
case REPEAT_BYTE_STATE:
SkASSERT(stateCount > 0);
register_memset_count(stateCount);
PB_MEMSET(dst, *src++, stateCount);
break;
case COPY_SRC_STATE:
SkASSERT(stateCount > 0);
register_memcpy_count(stateCount);
PB_MEMCPY(dst, src, stateCount);
src += stateCount;
break;
default:
SkASSERT(stateCount == 0);
break;
}
dst += stateCount;
dstWrite -= stateCount;
// copy at most dstWrite bytes into dst[]
while (dstWrite > 0) {
size_t n = *src++;
if (n <= 127) { // repeat count (n + 1)
n += 1;
if (n > dstWrite) {
n = dstWrite;
}
register_memset_count(n);
PB_MEMSET(dst, *src++, n);
} else { // same count (n - 127)
n -= 127;
if (n > dstWrite) {
n = dstWrite;
}
register_memcpy_count(n);
PB_MEMCPY(dst, src, n);
src += n;
}
dst += n;
dstWrite -= n;
}
SkASSERT(0 == dstWrite);
}

7
src/effects/SkTableColorFilter.cpp
View File

@ -201,8 +201,8 @@ static const uint8_t gCountNibBits[] = {
void SkTable_ColorFilter::flatten(SkWriteBuffer& buffer) const {
uint8_t storage[5*256];
int count = gCountNibBits[fFlags & 0xF];
size_t size = SkPackBits::Pack8(fStorage, count * 256, storage);
SkASSERT(size <= sizeof(storage));
size_t size = SkPackBits::Pack8(fStorage, count * 256, storage,
sizeof(storage));
buffer.write32(fFlags);
buffer.writeByteArray(storage, size);
@ -223,7 +223,8 @@ SkFlattenable* SkTable_ColorFilter::CreateProc(SkReadBuffer& buffer) {
}
uint8_t unpackedStorage[4*256];
size_t unpackedSize = SkPackBits::Unpack8(packedStorage, packedSize, unpackedStorage);
size_t unpackedSize = SkPackBits::Unpack8(packedStorage, packedSize,
unpackedStorage, sizeof(unpackedStorage));
// now check that we got the size we expected
if (!buffer.validate(unpackedSize == count*256)) {
return NULL;

74
tests/PackBitsTest.cpp
View File

@ -8,57 +8,8 @@
#include "SkPackBits.h"
#include "Test.h"
static const uint16_t gTest0[] = { 0, 0, 1, 1 };
static const uint16_t gTest1[] = { 1, 2, 3, 4, 5, 6 };
static const uint16_t gTest2[] = { 0, 0, 0, 1, 2, 3, 3, 3 };
static const uint16_t gTest3[] = { 0, 0, 0, 0, 0, 0, 1, 2, 3, 3, 3, 0, 0, 1 };
#include "SkRandom.h"
static SkRandom gRand;
static void rand_fill(uint16_t buffer[], int count) {
for (int i = 0; i < count; i++)
buffer[i] = (uint16_t)gRand.nextU();
}
static void test_pack16(skiatest::Reporter* reporter) {
static const struct {
const uint16_t* fSrc;
int fCount;
} gTests[] = {
{ gTest0, SK_ARRAY_COUNT(gTest0) },
{ gTest1, SK_ARRAY_COUNT(gTest1) },
{ gTest2, SK_ARRAY_COUNT(gTest2) },
{ gTest3, SK_ARRAY_COUNT(gTest3) }
};
for (size_t i = 0; i < SK_ARRAY_COUNT(gTests); i++) {
uint8_t dst[100];
size_t dstSize = SkPackBits::Pack16(gTests[i].fSrc,
gTests[i].fCount, dst);
uint16_t src[100];
int srcCount = SkPackBits::Unpack16(dst, dstSize, src);
bool match = gTests[i].fCount == srcCount && memcmp(gTests[i].fSrc, src,
gTests[i].fCount * sizeof(uint16_t)) == 0;
REPORTER_ASSERT(reporter, match);
}
for (int n = 1000; n; n--) {
int size = 50;
uint16_t src[100], src2[100];
uint8_t dst[200];
rand_fill(src, size);
size_t dstSize = SkPackBits::Pack16(src, size, dst);
size_t maxSize = SkPackBits::ComputeMaxSize16(size);
REPORTER_ASSERT(reporter, maxSize >= dstSize);
int srcCount = SkPackBits::Unpack16(dst, dstSize, src2);
REPORTER_ASSERT(reporter, size == srcCount);
bool match = memcmp(src, src2, size * sizeof(uint16_t)) == 0;
REPORTER_ASSERT(reporter, match);
}
}
static const uint8_t gTest80[] = { 0, 0, 1, 1 };
static const uint8_t gTest81[] = { 1, 2, 3, 4, 5, 6 };
static const uint8_t gTest82[] = { 0, 0, 0, 1, 2, 3, 3, 3 };
@ -86,10 +37,15 @@ static void test_pack8(skiatest::Reporter* reporter) {
uint8_t dst[100];
size_t maxSize = SkPackBits::ComputeMaxSize8(gTests[i].fCount);
size_t dstSize = SkPackBits::Pack8(gTests[i].fSrc,
gTests[i].fCount, dst);
gTests[i].fCount, dst, maxSize - 1);
REPORTER_ASSERT(reporter, dstSize == 0);
dstSize = SkPackBits::Pack8(gTests[i].fSrc,
gTests[i].fCount, dst, sizeof(dst));
REPORTER_ASSERT(reporter, dstSize <= maxSize);
uint8_t src[100];
int srcCount = SkPackBits::Unpack8(dst, dstSize, src);
int srcCount = SkPackBits::Unpack8(dst, dstSize, src, gTests[i].fCount - 1);
REPORTER_ASSERT(reporter, srcCount == 0);
srcCount = SkPackBits::Unpack8(dst, dstSize, src, sizeof(src));
bool match = gTests[i].fCount == srcCount &&
memcmp(gTests[i].fSrc, src,
gTests[i].fCount * sizeof(uint8_t)) == 0;
@ -102,30 +58,18 @@ static void test_pack8(skiatest::Reporter* reporter) {
uint8_t dst[600];
rand_fill(src, size);
size_t dstSize = SkPackBits::Pack8(src, size, dst);
size_t dstSize = SkPackBits::Pack8(src, size, dst, sizeof(dst));
size_t maxSize = SkPackBits::ComputeMaxSize8(size);
REPORTER_ASSERT(reporter, maxSize >= dstSize);
size_t srcCount = SkPackBits::Unpack8(dst, dstSize, src2);
size_t srcCount = SkPackBits::Unpack8(dst, dstSize, src2, size);
REPORTER_ASSERT(reporter, size == srcCount);
bool match = memcmp(src, src2, size * sizeof(uint8_t)) == 0;
REPORTER_ASSERT(reporter, match);
for (int j = 0; j < 100; j++) {
uint32_t skip = gRand.nextU() % size;
uint32_t write = gRand.nextU() % size;
if (skip + write > size) {
write = size - skip;
}
SkPackBits::Unpack8(src, skip, write, dst);
bool match = memcmp(src, src2 + skip, write) == 0;
REPORTER_ASSERT(reporter, match);
}
}
}
}
DEF_TEST(PackBits, reporter) {
test_pack8(reporter);
test_pack16(reporter);
}