From 50b790c6d4d759c77157317ef768baf86f1544c9 Mon Sep 17 00:00:00 2001
From: Igor Canadi <icanadi@fb.com>
Date: Tue, 19 Aug 2014 06:48:21 -0700
Subject: [PATCH] Removing BitStream* functions

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
---
 util/coding.cc | 88 --------------------------------------------------
 util/coding.h  | 36 ---------------------
 2 files changed, 124 deletions(-)

diff --git a/util/coding.cc b/util/coding.cc
index 31ae0e356..f09e67284 100644
--- a/util/coding.cc
+++ b/util/coding.cc
@@ -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
diff --git a/util/coding.h b/util/coding.h
index 6ad2077d4..fa6652668 100644
--- a/util/coding.h
+++ b/util/coding.h
@@ -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