diff options
Diffstat (limited to 'tensorflow/core/lib/core/coding.cc')
-rw-r--r-- | tensorflow/core/lib/core/coding.cc | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/tensorflow/core/lib/core/coding.cc b/tensorflow/core/lib/core/coding.cc new file mode 100644 index 0000000000..efff554742 --- /dev/null +++ b/tensorflow/core/lib/core/coding.cc @@ -0,0 +1,164 @@ +#include "tensorflow/core/lib/core/coding.h" + +namespace tensorflow { +namespace core { + +void EncodeFixed32(char* buf, uint32 value) { + if (port::kLittleEndian) { + memcpy(buf, &value, sizeof(value)); + } else { + buf[0] = value & 0xff; + buf[1] = (value >> 8) & 0xff; + buf[2] = (value >> 16) & 0xff; + buf[3] = (value >> 24) & 0xff; + } +} + +void EncodeFixed64(char* buf, uint64 value) { + if (port::kLittleEndian) { + memcpy(buf, &value, sizeof(value)); + } else { + buf[0] = value & 0xff; + buf[1] = (value >> 8) & 0xff; + buf[2] = (value >> 16) & 0xff; + buf[3] = (value >> 24) & 0xff; + buf[4] = (value >> 32) & 0xff; + buf[5] = (value >> 40) & 0xff; + buf[6] = (value >> 48) & 0xff; + buf[7] = (value >> 56) & 0xff; + } +} + +void PutFixed32(string* dst, uint32 value) { + char buf[sizeof(value)]; + EncodeFixed32(buf, value); + dst->append(buf, sizeof(buf)); +} + +void PutFixed64(string* dst, uint64 value) { + char buf[sizeof(value)]; + EncodeFixed64(buf, value); + dst->append(buf, sizeof(buf)); +} + +char* EncodeVarint32(char* dst, uint32 v) { + // Operate on characters as unsigneds + unsigned char* ptr = reinterpret_cast<unsigned char*>(dst); + static const int B = 128; + if (v < (1 << 7)) { + *(ptr++) = v; + } else if (v < (1 << 14)) { + *(ptr++) = v | B; + *(ptr++) = v >> 7; + } else if (v < (1 << 21)) { + *(ptr++) = v | B; + *(ptr++) = (v >> 7) | B; + *(ptr++) = v >> 14; + } else if (v < (1 << 28)) { + *(ptr++) = v | B; + *(ptr++) = (v >> 7) | B; + *(ptr++) = (v >> 14) | B; + *(ptr++) = v >> 21; + } else { + *(ptr++) = v | B; + *(ptr++) = (v >> 7) | B; + *(ptr++) = (v >> 14) | B; + *(ptr++) = (v >> 21) | B; + *(ptr++) = v >> 28; + } + return reinterpret_cast<char*>(ptr); +} + +void PutVarint32(string* dst, uint32 v) { + char buf[5]; + char* ptr = EncodeVarint32(buf, v); + dst->append(buf, ptr - buf); +} + +char* EncodeVarint64(char* dst, uint64 v) { + static const int B = 128; + unsigned char* ptr = reinterpret_cast<unsigned char*>(dst); + while (v >= B) { + *(ptr++) = (v & (B - 1)) | B; + v >>= 7; + } + *(ptr++) = static_cast<unsigned char>(v); + return reinterpret_cast<char*>(ptr); +} + +void PutVarint64(string* dst, uint64 v) { + char buf[10]; + char* ptr = EncodeVarint64(buf, v); + dst->append(buf, ptr - buf); +} + +int VarintLength(uint64_t v) { + int len = 1; + while (v >= 128) { + v >>= 7; + len++; + } + return len; +} + +const char* GetVarint32PtrFallback(const char* p, const char* limit, + uint32* value) { + uint32 result = 0; + for (uint32 shift = 0; shift <= 28 && p < limit; shift += 7) { + uint32 byte = *(reinterpret_cast<const unsigned char*>(p)); + p++; + if (byte & 128) { + // More bytes are present + result |= ((byte & 127) << shift); + } else { + result |= (byte << shift); + *value = result; + return reinterpret_cast<const char*>(p); + } + } + return NULL; +} + +bool GetVarint32(StringPiece* input, uint32* value) { + const char* p = input->data(); + const char* limit = p + input->size(); + const char* q = GetVarint32Ptr(p, limit, value); + if (q == NULL) { + return false; + } else { + *input = StringPiece(q, limit - q); + return true; + } +} + +const char* GetVarint64Ptr(const char* p, const char* limit, uint64* value) { + uint64 result = 0; + for (uint32 shift = 0; shift <= 63 && p < limit; shift += 7) { + uint64 byte = *(reinterpret_cast<const unsigned char*>(p)); + p++; + if (byte & 128) { + // More bytes are present + result |= ((byte & 127) << shift); + } else { + result |= (byte << shift); + *value = result; + return reinterpret_cast<const char*>(p); + } + } + return NULL; +} + +bool GetVarint64(StringPiece* input, uint64* value) { + const char* p = input->data(); + const char* limit = p + input->size(); + const char* q = GetVarint64Ptr(p, limit, value); + if (q == NULL) { + return false; + } else { + *input = StringPiece(q, limit - q); + return true; + } +} + +} // namespace core +} // namespace tensorflow |