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Removing BitStream* functions

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Summary: I was checking some functions in coding.h and coding.cc when I noticed these unused functions. Let's remove them.

Test Plan: compiles

Reviewers: sdong, ljin, yhchiang, dhruba

Reviewed By: dhruba

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22077
This commit is contained in:
Igor Canadi 2014-08-19 06:48:21 -07:00
parent 162b8151f1
commit 50b790c6d4
2 changed files with 0 additions and 124 deletions
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88
util/coding.cc
View File

@ -78,92 +78,4 @@ const char* GetVarint64Ptr(const char* p, const char* limit, uint64_t* value) {
return nullptr;
}
void BitStreamPutInt(char* dst, size_t dstlen, size_t offset,
uint32_t bits, uint64_t value) {
assert((offset + bits + 7)/8 <= dstlen);
assert(bits <= 64);
unsigned char* ptr = reinterpret_cast<unsigned char*>(dst);
size_t byteOffset = offset / 8;
size_t bitOffset = offset % 8;
// This prevents unused variable warnings when compiling.
#ifndef NDEBUG
// Store truncated value.
uint64_t origValue = (bits < 64)?(value & (((uint64_t)1 << bits) - 1)):value;
uint32_t origBits = bits;
#endif
while (bits > 0) {
size_t bitsToGet = std::min<size_t>(bits, 8 - bitOffset);
unsigned char mask = ((1 << bitsToGet) - 1);
ptr[byteOffset] = (ptr[byteOffset] & ~(mask << bitOffset)) +
((value & mask) << bitOffset);
value >>= bitsToGet;
byteOffset += 1;
bitOffset = 0;
bits -= bitsToGet;
}
assert(origValue == BitStreamGetInt(dst, dstlen, offset, origBits));
}
uint64_t BitStreamGetInt(const char* src, size_t srclen, size_t offset,
uint32_t bits) {
assert((offset + bits + 7)/8 <= srclen);
assert(bits <= 64);
const unsigned char* ptr = reinterpret_cast<const unsigned char*>(src);
uint64_t result = 0;
size_t byteOffset = offset / 8;
size_t bitOffset = offset % 8;
size_t shift = 0;
while (bits > 0) {
size_t bitsToGet = std::min<size_t>(bits, 8 - bitOffset);
unsigned char mask = ((1 << bitsToGet) - 1);
result += (uint64_t)((ptr[byteOffset] >> bitOffset) & mask) << shift;
shift += bitsToGet;
byteOffset += 1;
bitOffset = 0;
bits -= bitsToGet;
}
return result;
}
void BitStreamPutInt(std::string* dst, size_t offset, uint32_t bits,
uint64_t value) {
assert((offset + bits + 7)/8 <= dst->size());
const size_t kTmpBufLen = sizeof(value) + 1;
char tmpBuf[kTmpBufLen];
// Number of bytes of tmpBuf being used
const size_t kUsedBytes = (offset%8 + bits)/8;
// Copy relevant parts of dst to tmpBuf
for (size_t idx = 0; idx <= kUsedBytes; ++idx) {
tmpBuf[idx] = (*dst)[offset/8 + idx];
}
BitStreamPutInt(tmpBuf, kTmpBufLen, offset%8, bits, value);
// Copy tmpBuf back to dst
for (size_t idx = 0; idx <= kUsedBytes; ++idx) {
(*dst)[offset/8 + idx] = tmpBuf[idx];
}
// Do the check here too as we are working with a buffer.
assert(((bits < 64)?(value & (((uint64_t)1 << bits) - 1)):value) ==
BitStreamGetInt(dst, offset, bits));
}
} // namespace rocksdb

36
util/coding.h
View File

@ -115,32 +115,6 @@ inline const char* GetVarint32Ptr(const char* p,
return GetVarint32PtrFallback(p, limit, value);
}
// Writes an unsigned integer with bits number of bits with its least
// significant bit at offset.
// Bits are numbered from 0 to 7 in the first byte, 8 to 15 in the second and
// so on.
// value is truncated to the bits number of least significant bits.
// REQUIRES: (offset+bits+7)/8 <= dstlen
// REQUIRES: bits <= 64
extern void BitStreamPutInt(char* dst, size_t dstlen, size_t offset,
uint32_t bits, uint64_t value);
// Reads an unsigned integer with bits number of bits with its least
// significant bit at offset.
// Bits are numbered in the same way as ByteStreamPutInt().
// REQUIRES: (offset+bits+7)/8 <= srclen
// REQUIRES: bits <= 64
extern uint64_t BitStreamGetInt(const char* src, size_t srclen, size_t offset,
uint32_t bits);
// Convenience functions
extern void BitStreamPutInt(std::string* dst, size_t offset, uint32_t bits,
uint64_t value);
extern uint64_t BitStreamGetInt(const std::string* src, size_t offset,
uint32_t bits);
extern uint64_t BitStreamGetInt(const Slice* src, size_t offset,
uint32_t bits);
// -- Implementation of the functions declared above
inline void EncodeFixed32(char* buf, uint32_t value) {
#if __BYTE_ORDER == __LITTLE_ENDIAN
@ -291,14 +265,4 @@ inline Slice GetSliceUntil(Slice* slice, char delimiter) {
return ret;
}
inline uint64_t BitStreamGetInt(const std::string* src, size_t offset,
uint32_t bits) {
return BitStreamGetInt(src->data(), src->size(), offset, bits);
}
inline uint64_t BitStreamGetInt(const Slice* src, size_t offset,
uint32_t bits) {
return BitStreamGetInt(src->data(), src->size(), offset, bits);
}
} // namespace rocksdb