gecko/xpcom/io/nsSegmentedBuffer.h
Ehsan Akhgari 8c296bbcd4 Bug 579517 - Part 1: Automated conversion of NSPR numeric types to stdint types in Gecko; r=bsmedberg
This patch was generated by a script.  Here's the source of the script for
future reference:

function convert() {
echo "Converting $1 to $2..."
find . ! -wholename "*nsprpub*" \
       ! -wholename "*security/nss*" \
       ! -wholename "*/.hg*" \
       ! -wholename "obj-ff-dbg*" \
       ! -name nsXPCOMCID.h \
       ! -name prtypes.h \
         -type f \
      \( -iname "*.cpp" \
         -o -iname "*.h" \
         -o -iname "*.c" \
         -o -iname "*.cc" \
         -o -iname "*.idl" \
         -o -iname "*.ipdl" \
         -o -iname "*.ipdlh" \
         -o -iname "*.mm" \) | \
    xargs -n 1 sed -i -e "s/\b$1\b/$2/g"
}

convert PRInt8 int8_t
convert PRUint8 uint8_t
convert PRInt16 int16_t
convert PRUint16 uint16_t
convert PRInt32 int32_t
convert PRUint32 uint32_t
convert PRInt64 int64_t
convert PRUint64 uint64_t

convert PRIntn int
convert PRUintn unsigned

convert PRSize size_t

convert PROffset32 int32_t
convert PROffset64 int64_t

convert PRPtrdiff ptrdiff_t

convert PRFloat64 double
2012-08-22 11:56:38 -04:00

94 lines
3.1 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef nsSegmentedBuffer_h__
#define nsSegmentedBuffer_h__
#include "nsMemory.h"
#include "prclist.h"
class nsSegmentedBuffer
{
public:
nsSegmentedBuffer()
: mSegmentSize(0), mMaxSize(0),
mSegAllocator(nullptr), mSegmentArray(nullptr),
mSegmentArrayCount(0),
mFirstSegmentIndex(0), mLastSegmentIndex(0) {}
~nsSegmentedBuffer() {
Empty();
NS_IF_RELEASE(mSegAllocator);
}
nsresult Init(uint32_t segmentSize, uint32_t maxSize,
nsIMemory* allocator = nullptr);
char* AppendNewSegment(); // pushes at end
// returns true if no more segments remain:
bool DeleteFirstSegment(); // pops from beginning
// returns true if no more segments remain:
bool DeleteLastSegment(); // pops from beginning
// Call Realloc() on last segment. This is used to reduce memory
// consumption when data is not an exact multiple of segment size.
bool ReallocLastSegment(size_t newSize);
void Empty(); // frees all segments
inline uint32_t GetSegmentCount() {
if (mFirstSegmentIndex <= mLastSegmentIndex)
return mLastSegmentIndex - mFirstSegmentIndex;
else
return mSegmentArrayCount + mLastSegmentIndex - mFirstSegmentIndex;
}
inline uint32_t GetSegmentSize() { return mSegmentSize; }
inline uint32_t GetMaxSize() { return mMaxSize; }
inline uint32_t GetSize() { return GetSegmentCount() * mSegmentSize; }
inline char* GetSegment(uint32_t indx) {
NS_ASSERTION(indx < GetSegmentCount(), "index out of bounds");
int32_t i = ModSegArraySize(mFirstSegmentIndex + (int32_t)indx);
return mSegmentArray[i];
}
protected:
inline int32_t ModSegArraySize(int32_t n) {
uint32_t result = n & (mSegmentArrayCount - 1);
NS_ASSERTION(result == n % mSegmentArrayCount,
"non-power-of-2 mSegmentArrayCount");
return result;
}
inline bool IsFull() {
return ModSegArraySize(mLastSegmentIndex + 1) == mFirstSegmentIndex;
}
protected:
uint32_t mSegmentSize;
uint32_t mMaxSize;
nsIMemory* mSegAllocator;
char** mSegmentArray;
uint32_t mSegmentArrayCount;
int32_t mFirstSegmentIndex;
int32_t mLastSegmentIndex;
};
// NS_SEGMENTARRAY_INITIAL_SIZE: This number needs to start out as a
// power of 2 given how it gets used. We double the segment array
// when we overflow it, and use that fact that it's a power of 2
// to compute a fast modulus operation in IsFull.
//
// 32 segment array entries can accommodate 128k of data if segments
// are 4k in size. That seems like a reasonable amount that will avoid
// needing to grow the segment array.
#define NS_SEGMENTARRAY_INITIAL_COUNT 32
#endif // nsSegmentedBuffer_h__