icuSources/common/bytestream.cpp

   1 // Copyright (C) 2009-2010, 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 char* ByteSink::GetAppendBuffer(int32_t min_capacity,
  14                                 int32_t /*desired_capacity_hint*/,
  15                                 char* scratch, int32_t scratch_capacity,
  16                                 int32_t* result_capacity) {
  17   if (min_capacity < 1 || scratch_capacity < min_capacity) {
  18     *result_capacity = 0;
  19     return NULL;
  20   }
  21   *result_capacity = scratch_capacity;
  22   return scratch;
  23 }
  24
  25 void ByteSink::Flush() {}
  26
  27 CheckedArrayByteSink::CheckedArrayByteSink(char* outbuf, int32_t capacity)
  28     : outbuf_(outbuf), capacity_(capacity < 0 ? 0 : capacity),
  29       size_(0), appended_(0), overflowed_(FALSE) {
  30 }
  31
  32 CheckedArrayByteSink& CheckedArrayByteSink::Reset() {
  33   size_ = appended_ = 0;
  34   overflowed_ = FALSE;
  35   return *this;
  36 }
  37
  38 void CheckedArrayByteSink::Append(const char* bytes, int32_t n) {
  39   if (n <= 0) {
  40     return;
  41   }
  42   appended_ += n;
  43   int32_t available = capacity_ - size_;
  44   if (n > available) {
  45     n = available;
  46     overflowed_ = TRUE;
  47   }
  48   if (n > 0 && bytes != (outbuf_ + size_)) {
  49     uprv_memcpy(outbuf_ + size_, bytes, n);
  50   }
  51   size_ += n;
  52 }
  53
  54 char* CheckedArrayByteSink::GetAppendBuffer(int32_t min_capacity,
  55                                             int32_t /*desired_capacity_hint*/,
  56                                             char* scratch,
  57                                             int32_t scratch_capacity,
  58                                             int32_t* result_capacity) {
  59   if (min_capacity < 1 || scratch_capacity < min_capacity) {
  60     *result_capacity = 0;
  61     return NULL;
  62   }
  63   int32_t available = capacity_ - size_;
  64   if (available >= min_capacity) {
  65     *result_capacity = available;
  66     return outbuf_ + size_;
  67   } else {
  68     *result_capacity = scratch_capacity;
  69     return scratch;
  70   }
  71 }
  72
  73 U_NAMESPACE_END