a0e9ee5965
Summary: This diff adds rapidjson (https://code.google.com/p/rapidjson/) to RocksDB repository. First step to adding JSON is to add a JSON parser :) I'm not sure if rapidjson is the right choice. I only considered folly as an alternative. Using folly JSON parser has serious downsides. I tried extracting folly::json from the folly library. However, it depends on folly::dynamic, which basically depends on everything else. I would prefer to avoid adding complete folly library as RocksDB dependency. Folly has a lot of its own dependencies (https://github.com/facebook/folly) and also looks like open source world has some trouble installing it (https://groups.google.com/forum/#!forum/facebook-folly -- 60% of the posts are compile errors). We can discuss this if you think otherwise. RapidJSON does not have any dependencies whatsoever. No boost, no STL. We don't need to compile it since it's all header files. The performance results are also impressive: https://code.google.com/p/rapidjson/wiki/Performance. However, I'll make sure to write code in a way that we can easily switch JSON implementations going forward. Quora thread has some alternatives: http://www.quora.com/What-is-the-best-C-JSON-library Test Plan: none Reviewers: dhruba, haobo, yhchiang, sdong, jamesgpearce Reviewed By: haobo CC: leveldb Differential Revision: https://reviews.facebook.net/D18729
50 lines
1.3 KiB
C++
50 lines
1.3 KiB
C++
#ifndef RAPIDJSON_STRINGBUFFER_H_
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#define RAPIDJSON_STRINGBUFFER_H_
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#include "rapidjson.h"
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#include "internal/stack.h"
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namespace rapidjson {
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//! Represents an in-memory output stream.
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/*!
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\tparam Encoding Encoding of the stream.
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\tparam Allocator type for allocating memory buffer.
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\implements Stream
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*/
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template <typename Encoding, typename Allocator = CrtAllocator>
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struct GenericStringBuffer {
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typedef typename Encoding::Ch Ch;
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GenericStringBuffer(Allocator* allocator = 0, size_t capacity = kDefaultCapacity) : stack_(allocator, capacity) {}
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void Put(Ch c) { *stack_.template Push<Ch>() = c; }
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void Clear() { stack_.Clear(); }
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const char* GetString() const {
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// Push and pop a null terminator. This is safe.
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*stack_.template Push<Ch>() = '\0';
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stack_.template Pop<Ch>(1);
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return stack_.template Bottom<Ch>();
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}
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size_t Size() const { return stack_.GetSize(); }
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static const size_t kDefaultCapacity = 256;
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mutable internal::Stack<Allocator> stack_;
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};
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typedef GenericStringBuffer<UTF8<> > StringBuffer;
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//! Implement specialized version of PutN() with memset() for better performance.
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template<>
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inline void PutN(GenericStringBuffer<UTF8<> >& stream, char c, size_t n) {
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memset(stream.stack_.Push<char>(n), c, n * sizeof(c));
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}
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} // namespace rapidjson
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#endif // RAPIDJSON_STRINGBUFFER_H_
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