source/common/bytestream.cpp

   1 // Copyright (C) 2016 and later: Unicode, Inc. and others.
   2 // License & terms of use: http://www.unicode.org/copyright.html
   3 // Copyright (C) 2009-2011, International Business Machines
   4 // Corporation and others. All Rights Reserved.
   5 //
   6 // Copyright 2007 Google Inc. All Rights Reserved.
   7 // Author: sanjay@google.com (Sanjay Ghemawat)
   8
   9 #include "unicode/utypes.h"
  10 #include "unicode/bytestream.h"
  11 #include "cmemory.h"
  12
  13 U_NAMESPACE_BEGIN
  14
  15 ByteSink::~ByteSink() {}
  16
  17 char* ByteSink::GetAppendBuffer(int32_t min_capacity,
  18                                 int32_t /*desired_capacity_hint*/,
  19                                 char* scratch, int32_t scratch_capacity,
  20                                 int32_t* result_capacity) {
  21   if (min_capacity < 1 || scratch_capacity < min_capacity) {
  22     *result_capacity = 0;
  23     return NULL;
  24   }
  25   *result_capacity = scratch_capacity;
  26   return scratch;
  27 }
  28
  29 void ByteSink::Flush() {}
  30
  31 CheckedArrayByteSink::CheckedArrayByteSink(char* outbuf, int32_t capacity)
  32     : outbuf_(outbuf), capacity_(capacity < 0 ? 0 : capacity),
  33       size_(0), appended_(0), overflowed_(FALSE) {
  34 }
  35
  36 CheckedArrayByteSink::~CheckedArrayByteSink() {}
  37
  38 CheckedArrayByteSink& CheckedArrayByteSink::Reset() {
  39   size_ = appended_ = 0;
  40   overflowed_ = FALSE;
  41   return *this;
  42 }
  43
  44 void CheckedArrayByteSink::Append(const char* bytes, int32_t n) {
  45   if (n <= 0) {
  46     return;
  47   }
  48   appended_ += n;
  49   int32_t available = capacity_ - size_;
  50   if (n > available) {
  51     n = available;
  52     overflowed_ = TRUE;
  53   }
  54   if (n > 0 && bytes != (outbuf_ + size_)) {
  55     uprv_memcpy(outbuf_ + size_, bytes, n);
  56   }
  57   size_ += n;
  58 }
  59
  60 char* CheckedArrayByteSink::GetAppendBuffer(int32_t min_capacity,
  61                                             int32_t /*desired_capacity_hint*/,
  62                                             char* scratch,
  63                                             int32_t scratch_capacity,
  64                                             int32_t* result_capacity) {
  65   if (min_capacity < 1 || scratch_capacity < min_capacity) {
  66     *result_capacity = 0;
  67     return NULL;
  68   }
  69   int32_t available = capacity_ - size_;
  70   if (available >= min_capacity) {
  71     *result_capacity = available;
  72     return outbuf_ + size_;
  73   } else {
  74     *result_capacity = scratch_capacity;
  75     return scratch;
  76   }
  77 }
  78
  79 U_NAMESPACE_END