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Diffstat (limited to 'src/streams.h')
| -rw-r--r-- | src/streams.h | 707 |
1 files changed, 707 insertions, 0 deletions
diff --git a/src/streams.h b/src/streams.h new file mode 100644 index 0000000000..2dcca6646d --- /dev/null +++ b/src/streams.h @@ -0,0 +1,707 @@ +// Copyright (c) 2009-2010 Satoshi Nakamoto +// Copyright (c) 2009-2018 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#ifndef BITCOIN_STREAMS_H +#define BITCOIN_STREAMS_H + +#include <support/allocators/zeroafterfree.h> +#include <serialize.h> + +#include <algorithm> +#include <assert.h> +#include <ios> +#include <limits> +#include <map> +#include <set> +#include <stdint.h> +#include <stdio.h> +#include <string> +#include <string.h> +#include <utility> +#include <vector> + +template<typename Stream> +class OverrideStream +{ + Stream* stream; + + const int nType; + const int nVersion; + +public: + OverrideStream(Stream* stream_, int nType_, int nVersion_) : stream(stream_), nType(nType_), nVersion(nVersion_) {} + + template<typename T> + OverrideStream<Stream>& operator<<(const T& obj) + { + // Serialize to this stream + ::Serialize(*this, obj); + return (*this); + } + + template<typename T> + OverrideStream<Stream>& operator>>(T&& obj) + { + // Unserialize from this stream + ::Unserialize(*this, obj); + return (*this); + } + + void write(const char* pch, size_t nSize) + { + stream->write(pch, nSize); + } + + void read(char* pch, size_t nSize) + { + stream->read(pch, nSize); + } + + int GetVersion() const { return nVersion; } + int GetType() const { return nType; } +}; + +template<typename S> +OverrideStream<S> WithOrVersion(S* s, int nVersionFlag) +{ + return OverrideStream<S>(s, s->GetType(), s->GetVersion() | nVersionFlag); +} + +/* Minimal stream for overwriting and/or appending to an existing byte vector + * + * The referenced vector will grow as necessary + */ +class CVectorWriter +{ + public: + +/* + * @param[in] nTypeIn Serialization Type + * @param[in] nVersionIn Serialization Version (including any flags) + * @param[in] vchDataIn Referenced byte vector to overwrite/append + * @param[in] nPosIn Starting position. Vector index where writes should start. The vector will initially + * grow as necessary to max(nPosIn, vec.size()). So to append, use vec.size(). +*/ + CVectorWriter(int nTypeIn, int nVersionIn, std::vector<unsigned char>& vchDataIn, size_t nPosIn) : nType(nTypeIn), nVersion(nVersionIn), vchData(vchDataIn), nPos(nPosIn) + { + if(nPos > vchData.size()) + vchData.resize(nPos); + } +/* + * (other params same as above) + * @param[in] args A list of items to serialize starting at nPosIn. +*/ + template <typename... Args> + CVectorWriter(int nTypeIn, int nVersionIn, std::vector<unsigned char>& vchDataIn, size_t nPosIn, Args&&... args) : CVectorWriter(nTypeIn, nVersionIn, vchDataIn, nPosIn) + { + ::SerializeMany(*this, std::forward<Args>(args)...); + } + void write(const char* pch, size_t nSize) + { + assert(nPos <= vchData.size()); + size_t nOverwrite = std::min(nSize, vchData.size() - nPos); + if (nOverwrite) { + memcpy(vchData.data() + nPos, reinterpret_cast<const unsigned char*>(pch), nOverwrite); + } + if (nOverwrite < nSize) { + vchData.insert(vchData.end(), reinterpret_cast<const unsigned char*>(pch) + nOverwrite, reinterpret_cast<const unsigned char*>(pch) + nSize); + } + nPos += nSize; + } + template<typename T> + CVectorWriter& operator<<(const T& obj) + { + // Serialize to this stream + ::Serialize(*this, obj); + return (*this); + } + int GetVersion() const + { + return nVersion; + } + int GetType() const + { + return nType; + } + void seek(size_t nSize) + { + nPos += nSize; + if(nPos > vchData.size()) + vchData.resize(nPos); + } +private: + const int nType; + const int nVersion; + std::vector<unsigned char>& vchData; + size_t nPos; +}; + +/** Double ended buffer combining vector and stream-like interfaces. + * + * >> and << read and write unformatted data using the above serialization templates. + * Fills with data in linear time; some stringstream implementations take N^2 time. + */ +class CDataStream +{ +protected: + typedef CSerializeData vector_type; + vector_type vch; + unsigned int nReadPos; + + int nType; + int nVersion; +public: + + typedef vector_type::allocator_type allocator_type; + typedef vector_type::size_type size_type; + typedef vector_type::difference_type difference_type; + typedef vector_type::reference reference; + typedef vector_type::const_reference const_reference; + typedef vector_type::value_type value_type; + typedef vector_type::iterator iterator; + typedef vector_type::const_iterator const_iterator; + typedef vector_type::reverse_iterator reverse_iterator; + + explicit CDataStream(int nTypeIn, int nVersionIn) + { + Init(nTypeIn, nVersionIn); + } + + CDataStream(const_iterator pbegin, const_iterator pend, int nTypeIn, int nVersionIn) : vch(pbegin, pend) + { + Init(nTypeIn, nVersionIn); + } + + CDataStream(const char* pbegin, const char* pend, int nTypeIn, int nVersionIn) : vch(pbegin, pend) + { + Init(nTypeIn, nVersionIn); + } + + CDataStream(const vector_type& vchIn, int nTypeIn, int nVersionIn) : vch(vchIn.begin(), vchIn.end()) + { + Init(nTypeIn, nVersionIn); + } + + CDataStream(const std::vector<char>& vchIn, int nTypeIn, int nVersionIn) : vch(vchIn.begin(), vchIn.end()) + { + Init(nTypeIn, nVersionIn); + } + + CDataStream(const std::vector<unsigned char>& vchIn, int nTypeIn, int nVersionIn) : vch(vchIn.begin(), vchIn.end()) + { + Init(nTypeIn, nVersionIn); + } + + template <typename... Args> + CDataStream(int nTypeIn, int nVersionIn, Args&&... args) + { + Init(nTypeIn, nVersionIn); + ::SerializeMany(*this, std::forward<Args>(args)...); + } + + void Init(int nTypeIn, int nVersionIn) + { + nReadPos = 0; + nType = nTypeIn; + nVersion = nVersionIn; + } + + CDataStream& operator+=(const CDataStream& b) + { + vch.insert(vch.end(), b.begin(), b.end()); + return *this; + } + + friend CDataStream operator+(const CDataStream& a, const CDataStream& b) + { + CDataStream ret = a; + ret += b; + return (ret); + } + + std::string str() const + { + return (std::string(begin(), end())); + } + + + // + // Vector subset + // + const_iterator begin() const { return vch.begin() + nReadPos; } + iterator begin() { return vch.begin() + nReadPos; } + const_iterator end() const { return vch.end(); } + iterator end() { return vch.end(); } + size_type size() const { return vch.size() - nReadPos; } + bool empty() const { return vch.size() == nReadPos; } + void resize(size_type n, value_type c=0) { vch.resize(n + nReadPos, c); } + void reserve(size_type n) { vch.reserve(n + nReadPos); } + const_reference operator[](size_type pos) const { return vch[pos + nReadPos]; } + reference operator[](size_type pos) { return vch[pos + nReadPos]; } + void clear() { vch.clear(); nReadPos = 0; } + iterator insert(iterator it, const char x=char()) { return vch.insert(it, x); } + void insert(iterator it, size_type n, const char x) { vch.insert(it, n, x); } + value_type* data() { return vch.data() + nReadPos; } + const value_type* data() const { return vch.data() + nReadPos; } + + void insert(iterator it, std::vector<char>::const_iterator first, std::vector<char>::const_iterator last) + { + if (last == first) return; + assert(last - first > 0); + if (it == vch.begin() + nReadPos && (unsigned int)(last - first) <= nReadPos) + { + // special case for inserting at the front when there's room + nReadPos -= (last - first); + memcpy(&vch[nReadPos], &first[0], last - first); + } + else + vch.insert(it, first, last); + } + + void insert(iterator it, const char* first, const char* last) + { + if (last == first) return; + assert(last - first > 0); + if (it == vch.begin() + nReadPos && (unsigned int)(last - first) <= nReadPos) + { + // special case for inserting at the front when there's room + nReadPos -= (last - first); + memcpy(&vch[nReadPos], &first[0], last - first); + } + else + vch.insert(it, first, last); + } + + iterator erase(iterator it) + { + if (it == vch.begin() + nReadPos) + { + // special case for erasing from the front + if (++nReadPos >= vch.size()) + { + // whenever we reach the end, we take the opportunity to clear the buffer + nReadPos = 0; + return vch.erase(vch.begin(), vch.end()); + } + return vch.begin() + nReadPos; + } + else + return vch.erase(it); + } + + iterator erase(iterator first, iterator last) + { + if (first == vch.begin() + nReadPos) + { + // special case for erasing from the front + if (last == vch.end()) + { + nReadPos = 0; + return vch.erase(vch.begin(), vch.end()); + } + else + { + nReadPos = (last - vch.begin()); + return last; + } + } + else + return vch.erase(first, last); + } + + inline void Compact() + { + vch.erase(vch.begin(), vch.begin() + nReadPos); + nReadPos = 0; + } + + bool Rewind(size_type n) + { + // Rewind by n characters if the buffer hasn't been compacted yet + if (n > nReadPos) + return false; + nReadPos -= n; + return true; + } + + + // + // Stream subset + // + bool eof() const { return size() == 0; } + CDataStream* rdbuf() { return this; } + int in_avail() const { return size(); } + + void SetType(int n) { nType = n; } + int GetType() const { return nType; } + void SetVersion(int n) { nVersion = n; } + int GetVersion() const { return nVersion; } + + void read(char* pch, size_t nSize) + { + if (nSize == 0) return; + + // Read from the beginning of the buffer + unsigned int nReadPosNext = nReadPos + nSize; + if (nReadPosNext > vch.size()) { + throw std::ios_base::failure("CDataStream::read(): end of data"); + } + memcpy(pch, &vch[nReadPos], nSize); + if (nReadPosNext == vch.size()) + { + nReadPos = 0; + vch.clear(); + return; + } + nReadPos = nReadPosNext; + } + + void ignore(int nSize) + { + // Ignore from the beginning of the buffer + if (nSize < 0) { + throw std::ios_base::failure("CDataStream::ignore(): nSize negative"); + } + unsigned int nReadPosNext = nReadPos + nSize; + if (nReadPosNext >= vch.size()) + { + if (nReadPosNext > vch.size()) + throw std::ios_base::failure("CDataStream::ignore(): end of data"); + nReadPos = 0; + vch.clear(); + return; + } + nReadPos = nReadPosNext; + } + + void write(const char* pch, size_t nSize) + { + // Write to the end of the buffer + vch.insert(vch.end(), pch, pch + nSize); + } + + template<typename Stream> + void Serialize(Stream& s) const + { + // Special case: stream << stream concatenates like stream += stream + if (!vch.empty()) + s.write((char*)vch.data(), vch.size() * sizeof(value_type)); + } + + template<typename T> + CDataStream& operator<<(const T& obj) + { + // Serialize to this stream + ::Serialize(*this, obj); + return (*this); + } + + template<typename T> + CDataStream& operator>>(T&& obj) + { + // Unserialize from this stream + ::Unserialize(*this, obj); + return (*this); + } + + void GetAndClear(CSerializeData &d) { + d.insert(d.end(), begin(), end()); + clear(); + } + + /** + * XOR the contents of this stream with a certain key. + * + * @param[in] key The key used to XOR the data in this stream. + */ + void Xor(const std::vector<unsigned char>& key) + { + if (key.size() == 0) { + return; + } + + for (size_type i = 0, j = 0; i != size(); i++) { + vch[i] ^= key[j++]; + + // This potentially acts on very many bytes of data, so it's + // important that we calculate `j`, i.e. the `key` index in this + // way instead of doing a %, which would effectively be a division + // for each byte Xor'd -- much slower than need be. + if (j == key.size()) + j = 0; + } + } +}; + + + + + + + + + + +/** Non-refcounted RAII wrapper for FILE* + * + * Will automatically close the file when it goes out of scope if not null. + * If you're returning the file pointer, return file.release(). + * If you need to close the file early, use file.fclose() instead of fclose(file). + */ +class CAutoFile +{ +private: + const int nType; + const int nVersion; + + FILE* file; + +public: + CAutoFile(FILE* filenew, int nTypeIn, int nVersionIn) : nType(nTypeIn), nVersion(nVersionIn) + { + file = filenew; + } + + ~CAutoFile() + { + fclose(); + } + + // Disallow copies + CAutoFile(const CAutoFile&) = delete; + CAutoFile& operator=(const CAutoFile&) = delete; + + void fclose() + { + if (file) { + ::fclose(file); + file = nullptr; + } + } + + /** Get wrapped FILE* with transfer of ownership. + * @note This will invalidate the CAutoFile object, and makes it the responsibility of the caller + * of this function to clean up the returned FILE*. + */ + FILE* release() { FILE* ret = file; file = nullptr; return ret; } + + /** Get wrapped FILE* without transfer of ownership. + * @note Ownership of the FILE* will remain with this class. Use this only if the scope of the + * CAutoFile outlives use of the passed pointer. + */ + FILE* Get() const { return file; } + + /** Return true if the wrapped FILE* is nullptr, false otherwise. + */ + bool IsNull() const { return (file == nullptr); } + + // + // Stream subset + // + int GetType() const { return nType; } + int GetVersion() const { return nVersion; } + + void read(char* pch, size_t nSize) + { + if (!file) + throw std::ios_base::failure("CAutoFile::read: file handle is nullptr"); + if (fread(pch, 1, nSize, file) != nSize) + throw std::ios_base::failure(feof(file) ? "CAutoFile::read: end of file" : "CAutoFile::read: fread failed"); + } + + void ignore(size_t nSize) + { + if (!file) + throw std::ios_base::failure("CAutoFile::ignore: file handle is nullptr"); + unsigned char data[4096]; + while (nSize > 0) { + size_t nNow = std::min<size_t>(nSize, sizeof(data)); + if (fread(data, 1, nNow, file) != nNow) + throw std::ios_base::failure(feof(file) ? "CAutoFile::ignore: end of file" : "CAutoFile::read: fread failed"); + nSize -= nNow; + } + } + + void write(const char* pch, size_t nSize) + { + if (!file) + throw std::ios_base::failure("CAutoFile::write: file handle is nullptr"); + if (fwrite(pch, 1, nSize, file) != nSize) + throw std::ios_base::failure("CAutoFile::write: write failed"); + } + + template<typename T> + CAutoFile& operator<<(const T& obj) + { + // Serialize to this stream + if (!file) + throw std::ios_base::failure("CAutoFile::operator<<: file handle is nullptr"); + ::Serialize(*this, obj); + return (*this); + } + + template<typename T> + CAutoFile& operator>>(T&& obj) + { + // Unserialize from this stream + if (!file) + throw std::ios_base::failure("CAutoFile::operator>>: file handle is nullptr"); + ::Unserialize(*this, obj); + return (*this); + } +}; + +/** Non-refcounted RAII wrapper around a FILE* that implements a ring buffer to + * deserialize from. It guarantees the ability to rewind a given number of bytes. + * + * Will automatically close the file when it goes out of scope if not null. + * If you need to close the file early, use file.fclose() instead of fclose(file). + */ +class CBufferedFile +{ +private: + const int nType; + const int nVersion; + + FILE *src; // source file + uint64_t nSrcPos; // how many bytes have been read from source + uint64_t nReadPos; // how many bytes have been read from this + uint64_t nReadLimit; // up to which position we're allowed to read + uint64_t nRewind; // how many bytes we guarantee to rewind + std::vector<char> vchBuf; // the buffer + +protected: + // read data from the source to fill the buffer + bool Fill() { + unsigned int pos = nSrcPos % vchBuf.size(); + unsigned int readNow = vchBuf.size() - pos; + unsigned int nAvail = vchBuf.size() - (nSrcPos - nReadPos) - nRewind; + if (nAvail < readNow) + readNow = nAvail; + if (readNow == 0) + return false; + size_t nBytes = fread((void*)&vchBuf[pos], 1, readNow, src); + if (nBytes == 0) { + throw std::ios_base::failure(feof(src) ? "CBufferedFile::Fill: end of file" : "CBufferedFile::Fill: fread failed"); + } else { + nSrcPos += nBytes; + return true; + } + } + +public: + CBufferedFile(FILE *fileIn, uint64_t nBufSize, uint64_t nRewindIn, int nTypeIn, int nVersionIn) : + nType(nTypeIn), nVersion(nVersionIn), nSrcPos(0), nReadPos(0), nReadLimit((uint64_t)(-1)), nRewind(nRewindIn), vchBuf(nBufSize, 0) + { + src = fileIn; + } + + ~CBufferedFile() + { + fclose(); + } + + // Disallow copies + CBufferedFile(const CBufferedFile&) = delete; + CBufferedFile& operator=(const CBufferedFile&) = delete; + + int GetVersion() const { return nVersion; } + int GetType() const { return nType; } + + void fclose() + { + if (src) { + ::fclose(src); + src = nullptr; + } + } + + // check whether we're at the end of the source file + bool eof() const { + return nReadPos == nSrcPos && feof(src); + } + + // read a number of bytes + void read(char *pch, size_t nSize) { + if (nSize + nReadPos > nReadLimit) + throw std::ios_base::failure("Read attempted past buffer limit"); + if (nSize + nRewind > vchBuf.size()) + throw std::ios_base::failure("Read larger than buffer size"); + while (nSize > 0) { + if (nReadPos == nSrcPos) + Fill(); + unsigned int pos = nReadPos % vchBuf.size(); + size_t nNow = nSize; + if (nNow + pos > vchBuf.size()) + nNow = vchBuf.size() - pos; + if (nNow + nReadPos > nSrcPos) + nNow = nSrcPos - nReadPos; + memcpy(pch, &vchBuf[pos], nNow); + nReadPos += nNow; + pch += nNow; + nSize -= nNow; + } + } + + // return the current reading position + uint64_t GetPos() const { + return nReadPos; + } + + // rewind to a given reading position + bool SetPos(uint64_t nPos) { + nReadPos = nPos; + if (nReadPos + nRewind < nSrcPos) { + nReadPos = nSrcPos - nRewind; + return false; + } else if (nReadPos > nSrcPos) { + nReadPos = nSrcPos; + return false; + } else { + return true; + } + } + + bool Seek(uint64_t nPos) { + long nLongPos = nPos; + if (nPos != (uint64_t)nLongPos) + return false; + if (fseek(src, nLongPos, SEEK_SET)) + return false; + nLongPos = ftell(src); + nSrcPos = nLongPos; + nReadPos = nLongPos; + return true; + } + + // prevent reading beyond a certain position + // no argument removes the limit + bool SetLimit(uint64_t nPos = (uint64_t)(-1)) { + if (nPos < nReadPos) + return false; + nReadLimit = nPos; + return true; + } + + template<typename T> + CBufferedFile& operator>>(T&& obj) { + // Unserialize from this stream + ::Unserialize(*this, obj); + return (*this); + } + + // search for a given byte in the stream, and remain positioned on it + void FindByte(char ch) { + while (true) { + if (nReadPos == nSrcPos) + Fill(); + if (vchBuf[nReadPos % vchBuf.size()] == ch) + break; + nReadPos++; + } + } +}; + +#endif // BITCOIN_STREAMS_H |