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/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "Stream.hh"
#include <vector>
namespace avro {
using std::vector;
class MemoryInputStream : public InputStream {
const std::vector<uint8_t*>& data_;
const size_t chunkSize_;
const size_t size_;
const size_t available_;
size_t cur_;
size_t curLen_;
size_t maxLen() {
size_t n = (cur_ == (size_ - 1)) ? available_ : chunkSize_;
if (n == curLen_) {
if (cur_ == (size_ - 1)) {
return 0;
}
++cur_;
n = (cur_ == (size_ - 1)) ? available_ : chunkSize_;
curLen_ = 0;
}
return n;
}
public:
MemoryInputStream(const std::vector<uint8_t*>& b,
size_t chunkSize, size_t available) :
data_(b), chunkSize_(chunkSize), size_(b.size()),
available_(available), cur_(0), curLen_(0) { }
bool next(const uint8_t** data, size_t* len) {
if (size_t n = maxLen()) {
*data = data_[cur_] + curLen_;
*len = n - curLen_;
curLen_ = n;
return true;
}
return false;
}
void backup(size_t len) {
curLen_ -= len;
}
void skip(size_t len) {
while (len > 0) {
if (size_t n = maxLen()) {
if ((curLen_ + len) < n) {
n = curLen_ + len;
}
len -= n - curLen_;
curLen_ = n;
} else {
break;
}
}
}
size_t byteCount() const {
return cur_ * chunkSize_ + curLen_;
}
};
class MemoryInputStream2 : public InputStream {
const uint8_t* const data_;
const size_t size_;
size_t curLen_;
public:
MemoryInputStream2(const uint8_t *data, size_t len)
: data_(data), size_(len), curLen_(0) { }
bool next(const uint8_t** data, size_t* len) {
if (curLen_ == size_) {
return false;
}
*data = &data_[curLen_];
*len = size_ - curLen_;
curLen_ = size_;
return true;
}
void backup(size_t len) {
curLen_ -= len;
}
void skip(size_t len) {
if (len > (size_ - curLen_)) {
len = size_ - curLen_;
}
curLen_ += len;
}
size_t byteCount() const {
return curLen_;
}
};
class MemoryOutputStream : public OutputStream {
public:
const size_t chunkSize_;
std::vector<uint8_t*> data_;
size_t available_;
size_t byteCount_;
MemoryOutputStream(size_t chunkSize) : chunkSize_(chunkSize),
available_(0), byteCount_(0) { }
~MemoryOutputStream() {
for (std::vector<uint8_t*>::const_iterator it = data_.begin();
it != data_.end(); ++it) {
delete[] *it;
}
}
bool next(uint8_t** data, size_t* len) {
if (available_ == 0) {
data_.push_back(new uint8_t[chunkSize_]);
available_ = chunkSize_;
}
*data = &data_.back()[chunkSize_ - available_];
*len = available_;
byteCount_ += available_;
available_ = 0;
return true;
}
void backup(size_t len) {
available_ += len;
byteCount_ -= len;
}
uint64_t byteCount() const {
return byteCount_;
}
void flush() { }
};
std::unique_ptr<OutputStream> memoryOutputStream(size_t chunkSize)
{
return std::unique_ptr<OutputStream>(new MemoryOutputStream(chunkSize));
}
std::unique_ptr<InputStream> memoryInputStream(const uint8_t* data, size_t len)
{
return std::unique_ptr<InputStream>(new MemoryInputStream2(data, len));
}
std::unique_ptr<InputStream> memoryInputStream(const OutputStream& source)
{
const MemoryOutputStream& mos =
dynamic_cast<const MemoryOutputStream&>(source);
return (mos.data_.empty()) ?
std::unique_ptr<InputStream>(new MemoryInputStream2(0, 0)) :
std::unique_ptr<InputStream>(new MemoryInputStream(mos.data_,
mos.chunkSize_,
(mos.chunkSize_ - mos.available_)));
}
std::shared_ptr<std::vector<uint8_t> > snapshot(const OutputStream& source)
{
const MemoryOutputStream& mos =
dynamic_cast<const MemoryOutputStream&>(source);
std::shared_ptr<std::vector<uint8_t> > result(new std::vector<uint8_t>());
size_t c = mos.byteCount_;
result->reserve(mos.byteCount_);
for (vector<uint8_t*>::const_iterator it = mos.data_.begin();
it != mos.data_.end(); ++it) {
size_t n = std::min(c, mos.chunkSize_);
std::copy(*it, *it + n, std::back_inserter(*result));
c -= n;
}
return result;
}
} // namespace avro
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