icuSources/common/bytestream.cpp

   1 // Copyright (C) 2009-2011, International Business Machines
   2 // Corporation and others. All Rights Reserved.
   3 //
   4 // Copyright 2007 Google Inc. All Rights Reserved.
   5 // Author: sanjay@google.com (Sanjay Ghemawat)
   6
   7 #include "unicode/utypes.h"
   8 #include "unicode/bytestream.h"
   9 #include "cmemory.h"
  10
  11 U_NAMESPACE_BEGIN
  12
  13 ByteSink::~ByteSink() {}
  14
  15 char* ByteSink::GetAppendBuffer(int32_t min_capacity,
  16                                 int32_t /*desired_capacity_hint*/,
  17                                 char* scratch, int32_t scratch_capacity,
  18                                 int32_t* result_capacity) {
  19   if (min_capacity < 1 || scratch_capacity < min_capacity) {
  20     *result_capacity = 0;
  21     return NULL;
  22   }
  23   *result_capacity = scratch_capacity;
  24   return scratch;
  25 }
  26
  27 void ByteSink::Flush() {}
  28
  29 CheckedArrayByteSink::CheckedArrayByteSink(char* outbuf, int32_t capacity)
  30     : outbuf_(outbuf), capacity_(capacity < 0 ? 0 : capacity),
  31       size_(0), appended_(0), overflowed_(FALSE) {
  32 }
  33
  34 CheckedArrayByteSink::~CheckedArrayByteSink() {}
  35
  36 CheckedArrayByteSink& CheckedArrayByteSink::Reset() {
  37   size_ = appended_ = 0;
  38   overflowed_ = FALSE;
  39   return *this;
  40 }
  41
  42 void CheckedArrayByteSink::Append(const char* bytes, int32_t n) {
  43   if (n <= 0) {
  44     return;
  45   }
  46   appended_ += n;
  47   int32_t available = capacity_ - size_;
  48   if (n > available) {
  49     n = available;
  50     overflowed_ = TRUE;
  51   }
  52   if (n > 0 && bytes != (outbuf_ + size_)) {
  53     uprv_memcpy(outbuf_ + size_, bytes, n);
  54   }
  55   size_ += n;
  56 }
  57
  58 char* CheckedArrayByteSink::GetAppendBuffer(int32_t min_capacity,
  59                                             int32_t /*desired_capacity_hint*/,
  60                                             char* scratch,
  61                                             int32_t scratch_capacity,
  62                                             int32_t* result_capacity) {
  63   if (min_capacity < 1 || scratch_capacity < min_capacity) {
  64     *result_capacity = 0;
  65     return NULL;
  66   }
  67   int32_t available = capacity_ - size_;
  68   if (available >= min_capacity) {
  69     *result_capacity = available;
  70     return outbuf_ + size_;
  71   } else {
  72     *result_capacity = scratch_capacity;
  73     return scratch;
  74   }
  75 }
  76
  77 U_NAMESPACE_END