sink_mem.cc

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#include <cassert>
#include <cstring>
#include <string>

#include "util/smalloc.h"
#include "util/string.h"

#include "sink_mem.h"

namespace cvmfs {

MemSink::MemSink(size_t size) : Sink(true), size_(size),
                                pos_(0), max_size_(kMaxMemSize) {
  data_ = static_cast<unsigned char *>(smalloc(size));
}

int64_t MemSink::Write(const void *buf, uint64_t sz) {
  if (pos_ + sz > size_) {
    if (is_owner_) {
      size_t new_size = pos_ + sz < size_ * 2 ? size_ * 2 : pos_ + sz + 1;
      data_ = static_cast<unsigned char *>(srealloc(data_, new_size));
      size_ = new_size;
    } else {
      return -ENOSPC;
    }
  }

  memcpy(data_ + pos_, buf, sz);
  pos_ += sz;
  return static_cast<int64_t>(sz);
}

int MemSink::Reset() {
  if (is_owner_) {
    free(data_);
    data_ = NULL;
    size_ = 0;
  }

  pos_ = 0;

  return 0;
}

bool MemSink::IsValid() {
  return (size_ == 0 && pos_ == 0 && data_ == NULL) ||
          (size_ > 0 && pos_ >= 0 && data_ != NULL);
}

bool MemSink::Reserve(size_t size) {
  if (size <= size_) {
    pos_ = 0;
    return true;
  }
  if (!is_owner_ || size > max_size_) {
    return false;
  }

  FreeData();

  size_ = size;
  pos_ = 0;
  if (size == 0) {
    data_ = NULL;
  } else {
    data_ = static_cast<unsigned char *>(smalloc(size));
  }
  return true;
}

std::string MemSink::Describe() {
  std::string result = "Memory sink with ";
  result += "size: " + StringifyUint(size_);
  result += " - current pos: " + StringifyUint(pos_);
  return result;
}

void MemSink::Adopt(size_t size, size_t pos, unsigned char *data,
                    bool is_owner) {
  assert(size >= pos);

  FreeData();

  is_owner_ = is_owner;
  size_ = size;
  pos_ = pos;
  data_ = data;
}

}  // namespace cvmfs