Pieter Wuille
10 years ago
16 changed files with 589 additions and 553 deletions
@ -0,0 +1,571 @@
@@ -0,0 +1,571 @@
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// Copyright (c) 2009-2010 Satoshi Nakamoto
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// Copyright (c) 2009-2013 The Bitcoin developers
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// Distributed under the MIT/X11 software license, see the accompanying
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// file COPYING or http://www.opensource.org/licenses/mit-license.php.
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#ifndef BITCOIN_STREAMS_H |
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#define BITCOIN_STREAMS_H |
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#include "allocators.h" |
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#include "serialize.h" |
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#include <algorithm> |
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#include <assert.h> |
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#include <ios> |
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#include <limits> |
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#include <map> |
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#include <set> |
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#include <stdint.h> |
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#include <string> |
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#include <string.h> |
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#include <utility> |
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#include <vector> |
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/** Double ended buffer combining vector and stream-like interfaces.
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* |
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* >> and << read and write unformatted data using the above serialization templates. |
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* Fills with data in linear time; some stringstream implementations take N^2 time. |
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*/ |
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class CDataStream |
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{ |
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protected: |
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typedef CSerializeData vector_type; |
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vector_type vch; |
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unsigned int nReadPos; |
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public: |
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int nType; |
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int nVersion; |
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typedef vector_type::allocator_type allocator_type; |
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typedef vector_type::size_type size_type; |
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typedef vector_type::difference_type difference_type; |
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typedef vector_type::reference reference; |
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typedef vector_type::const_reference const_reference; |
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typedef vector_type::value_type value_type; |
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typedef vector_type::iterator iterator; |
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typedef vector_type::const_iterator const_iterator; |
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typedef vector_type::reverse_iterator reverse_iterator; |
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explicit CDataStream(int nTypeIn, int nVersionIn) |
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{ |
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Init(nTypeIn, nVersionIn); |
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} |
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CDataStream(const_iterator pbegin, const_iterator pend, int nTypeIn, int nVersionIn) : vch(pbegin, pend) |
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{ |
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Init(nTypeIn, nVersionIn); |
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} |
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#if !defined(_MSC_VER) || _MSC_VER >= 1300 |
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CDataStream(const char* pbegin, const char* pend, int nTypeIn, int nVersionIn) : vch(pbegin, pend) |
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{ |
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Init(nTypeIn, nVersionIn); |
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} |
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#endif |
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CDataStream(const vector_type& vchIn, int nTypeIn, int nVersionIn) : vch(vchIn.begin(), vchIn.end()) |
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{ |
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Init(nTypeIn, nVersionIn); |
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} |
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CDataStream(const std::vector<char>& vchIn, int nTypeIn, int nVersionIn) : vch(vchIn.begin(), vchIn.end()) |
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{ |
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Init(nTypeIn, nVersionIn); |
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} |
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CDataStream(const std::vector<unsigned char>& vchIn, int nTypeIn, int nVersionIn) : vch(vchIn.begin(), vchIn.end()) |
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{ |
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Init(nTypeIn, nVersionIn); |
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} |
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void Init(int nTypeIn, int nVersionIn) |
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{ |
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nReadPos = 0; |
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nType = nTypeIn; |
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nVersion = nVersionIn; |
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} |
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CDataStream& operator+=(const CDataStream& b) |
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{ |
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vch.insert(vch.end(), b.begin(), b.end()); |
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return *this; |
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} |
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friend CDataStream operator+(const CDataStream& a, const CDataStream& b) |
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{ |
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CDataStream ret = a; |
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ret += b; |
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return (ret); |
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} |
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std::string str() const |
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{ |
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return (std::string(begin(), end())); |
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} |
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//
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// Vector subset
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//
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const_iterator begin() const { return vch.begin() + nReadPos; } |
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iterator begin() { return vch.begin() + nReadPos; } |
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const_iterator end() const { return vch.end(); } |
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iterator end() { return vch.end(); } |
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size_type size() const { return vch.size() - nReadPos; } |
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bool empty() const { return vch.size() == nReadPos; } |
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void resize(size_type n, value_type c=0) { vch.resize(n + nReadPos, c); } |
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void reserve(size_type n) { vch.reserve(n + nReadPos); } |
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const_reference operator[](size_type pos) const { return vch[pos + nReadPos]; } |
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reference operator[](size_type pos) { return vch[pos + nReadPos]; } |
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void clear() { vch.clear(); nReadPos = 0; } |
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iterator insert(iterator it, const char& x=char()) { return vch.insert(it, x); } |
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void insert(iterator it, size_type n, const char& x) { vch.insert(it, n, x); } |
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void insert(iterator it, std::vector<char>::const_iterator first, std::vector<char>::const_iterator last) |
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{ |
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assert(last - first >= 0); |
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if (it == vch.begin() + nReadPos && (unsigned int)(last - first) <= nReadPos) |
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{ |
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// special case for inserting at the front when there's room
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nReadPos -= (last - first); |
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memcpy(&vch[nReadPos], &first[0], last - first); |
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} |
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else |
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vch.insert(it, first, last); |
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} |
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#if !defined(_MSC_VER) || _MSC_VER >= 1300 |
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void insert(iterator it, const char* first, const char* last) |
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{ |
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assert(last - first >= 0); |
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if (it == vch.begin() + nReadPos && (unsigned int)(last - first) <= nReadPos) |
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{ |
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// special case for inserting at the front when there's room
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nReadPos -= (last - first); |
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memcpy(&vch[nReadPos], &first[0], last - first); |
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} |
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else |
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vch.insert(it, first, last); |
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} |
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#endif |
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iterator erase(iterator it) |
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{ |
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if (it == vch.begin() + nReadPos) |
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{ |
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// special case for erasing from the front
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if (++nReadPos >= vch.size()) |
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{ |
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// whenever we reach the end, we take the opportunity to clear the buffer
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nReadPos = 0; |
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return vch.erase(vch.begin(), vch.end()); |
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} |
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return vch.begin() + nReadPos; |
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} |
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else |
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return vch.erase(it); |
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} |
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iterator erase(iterator first, iterator last) |
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{ |
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if (first == vch.begin() + nReadPos) |
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{ |
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// special case for erasing from the front
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if (last == vch.end()) |
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{ |
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nReadPos = 0; |
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return vch.erase(vch.begin(), vch.end()); |
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} |
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else |
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{ |
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nReadPos = (last - vch.begin()); |
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return last; |
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} |
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} |
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else |
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return vch.erase(first, last); |
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} |
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inline void Compact() |
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{ |
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vch.erase(vch.begin(), vch.begin() + nReadPos); |
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nReadPos = 0; |
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} |
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bool Rewind(size_type n) |
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{ |
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// Rewind by n characters if the buffer hasn't been compacted yet
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if (n > nReadPos) |
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return false; |
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nReadPos -= n; |
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return true; |
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} |
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//
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// Stream subset
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//
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bool eof() const { return size() == 0; } |
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CDataStream* rdbuf() { return this; } |
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int in_avail() { return size(); } |
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void SetType(int n) { nType = n; } |
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int GetType() { return nType; } |
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void SetVersion(int n) { nVersion = n; } |
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int GetVersion() { return nVersion; } |
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void ReadVersion() { *this >> nVersion; } |
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void WriteVersion() { *this << nVersion; } |
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CDataStream& read(char* pch, size_t nSize) |
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{ |
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// Read from the beginning of the buffer
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unsigned int nReadPosNext = nReadPos + nSize; |
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if (nReadPosNext >= vch.size()) |
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{ |
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if (nReadPosNext > vch.size()) |
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{ |
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throw std::ios_base::failure("CDataStream::read() : end of data"); |
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} |
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memcpy(pch, &vch[nReadPos], nSize); |
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nReadPos = 0; |
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vch.clear(); |
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return (*this); |
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} |
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memcpy(pch, &vch[nReadPos], nSize); |
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nReadPos = nReadPosNext; |
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return (*this); |
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} |
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CDataStream& ignore(int nSize) |
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{ |
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// Ignore from the beginning of the buffer
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assert(nSize >= 0); |
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unsigned int nReadPosNext = nReadPos + nSize; |
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if (nReadPosNext >= vch.size()) |
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{ |
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if (nReadPosNext > vch.size()) |
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throw std::ios_base::failure("CDataStream::ignore() : end of data"); |
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nReadPos = 0; |
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vch.clear(); |
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return (*this); |
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} |
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nReadPos = nReadPosNext; |
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return (*this); |
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} |
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CDataStream& write(const char* pch, size_t nSize) |
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{ |
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// Write to the end of the buffer
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vch.insert(vch.end(), pch, pch + nSize); |
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return (*this); |
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} |
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template<typename Stream> |
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void Serialize(Stream& s, int nType, int nVersion) const |
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{ |
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// Special case: stream << stream concatenates like stream += stream
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if (!vch.empty()) |
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s.write((char*)&vch[0], vch.size() * sizeof(vch[0])); |
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} |
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template<typename T> |
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unsigned int GetSerializeSize(const T& obj) |
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{ |
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// Tells the size of the object if serialized to this stream
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return ::GetSerializeSize(obj, nType, nVersion); |
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} |
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template<typename T> |
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CDataStream& operator<<(const T& obj) |
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{ |
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// Serialize to this stream
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::Serialize(*this, obj, nType, nVersion); |
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return (*this); |
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} |
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template<typename T> |
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CDataStream& operator>>(T& obj) |
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{ |
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// Unserialize from this stream
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::Unserialize(*this, obj, nType, nVersion); |
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return (*this); |
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} |
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void GetAndClear(CSerializeData &data) { |
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data.insert(data.end(), begin(), end()); |
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clear(); |
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} |
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}; |
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/** Non-refcounted RAII wrapper for FILE*
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* |
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* Will automatically close the file when it goes out of scope if not null. |
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* If you're returning the file pointer, return file.release(). |
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* If you need to close the file early, use file.fclose() instead of fclose(file). |
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*/ |
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class CAutoFile |
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{ |
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private: |
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// Disallow copies
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CAutoFile(const CAutoFile&); |
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CAutoFile& operator=(const CAutoFile&); |
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int nType; |
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int nVersion; |
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FILE* file; |
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public: |
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CAutoFile(FILE* filenew, int nTypeIn, int nVersionIn) |
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{ |
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file = filenew; |
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nType = nTypeIn; |
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nVersion = nVersionIn; |
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} |
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~CAutoFile() |
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{ |
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fclose(); |
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} |
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void fclose() |
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{ |
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if (file) { |
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::fclose(file); |
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file = NULL; |
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} |
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} |
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/** Get wrapped FILE* with transfer of ownership.
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* @note This will invalidate the CAutoFile object, and makes it the responsibility of the caller |
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* of this function to clean up the returned FILE*. |
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*/ |
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FILE* release() { FILE* ret = file; file = NULL; return ret; } |
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/** Get wrapped FILE* without transfer of ownership.
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* @note Ownership of the FILE* will remain with this class. Use this only if the scope of the |
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* CAutoFile outlives use of the passed pointer. |
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*/ |
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FILE* Get() const { return file; } |
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/** Return true if the wrapped FILE* is NULL, false otherwise.
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*/ |
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bool IsNull() const { return (file == NULL); } |
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//
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// Stream subset
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//
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void SetType(int n) { nType = n; } |
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int GetType() { return nType; } |
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void SetVersion(int n) { nVersion = n; } |
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int GetVersion() { return nVersion; } |
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void ReadVersion() { *this >> nVersion; } |
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void WriteVersion() { *this << nVersion; } |
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CAutoFile& read(char* pch, size_t nSize) |
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{ |
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if (!file) |
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throw std::ios_base::failure("CAutoFile::read : file handle is NULL"); |
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if (fread(pch, 1, nSize, file) != nSize) |
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throw std::ios_base::failure(feof(file) ? "CAutoFile::read : end of file" : "CAutoFile::read : fread failed"); |
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return (*this); |
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} |
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CAutoFile& write(const char* pch, size_t nSize) |
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{ |
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if (!file) |
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throw std::ios_base::failure("CAutoFile::write : file handle is NULL"); |
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if (fwrite(pch, 1, nSize, file) != nSize) |
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throw std::ios_base::failure("CAutoFile::write : write failed"); |
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return (*this); |
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} |
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template<typename T> |
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unsigned int GetSerializeSize(const T& obj) |
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{ |
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// Tells the size of the object if serialized to this stream
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return ::GetSerializeSize(obj, nType, nVersion); |
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} |
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template<typename T> |
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CAutoFile& operator<<(const T& obj) |
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{ |
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// Serialize to this stream
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if (!file) |
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throw std::ios_base::failure("CAutoFile::operator<< : file handle is NULL"); |
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::Serialize(*this, obj, nType, nVersion); |
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return (*this); |
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} |
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template<typename T> |
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CAutoFile& operator>>(T& obj) |
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{ |
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// Unserialize from this stream
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if (!file) |
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throw std::ios_base::failure("CAutoFile::operator>> : file handle is NULL"); |
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::Unserialize(*this, obj, nType, nVersion); |
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return (*this); |
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} |
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}; |
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/** Non-refcounted RAII wrapper around a FILE* that implements a ring buffer to
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* deserialize from. It guarantees the ability to rewind a given number of bytes. |
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* |
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* Will automatically close the file when it goes out of scope if not null. |
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* If you need to close the file early, use file.fclose() instead of fclose(file). |
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*/ |
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class CBufferedFile |
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{ |
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private: |
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// Disallow copies
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CBufferedFile(const CBufferedFile&); |
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CBufferedFile& operator=(const CBufferedFile&); |
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int nType; |
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int nVersion; |
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FILE *src; // source file
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uint64_t nSrcPos; // how many bytes have been read from source
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uint64_t nReadPos; // how many bytes have been read from this
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uint64_t nReadLimit; // up to which position we're allowed to read
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uint64_t nRewind; // how many bytes we guarantee to rewind
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std::vector<char> vchBuf; // the buffer
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protected: |
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// read data from the source to fill the buffer
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bool Fill() { |
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unsigned int pos = nSrcPos % vchBuf.size(); |
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unsigned int readNow = vchBuf.size() - pos; |
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unsigned int nAvail = vchBuf.size() - (nSrcPos - nReadPos) - nRewind; |
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if (nAvail < readNow) |
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readNow = nAvail; |
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if (readNow == 0) |
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return false; |
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size_t read = fread((void*)&vchBuf[pos], 1, readNow, src); |
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if (read == 0) { |
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throw std::ios_base::failure(feof(src) ? "CBufferedFile::Fill : end of file" : "CBufferedFile::Fill : fread failed"); |
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} else { |
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nSrcPos += read; |
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return true; |
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} |
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} |
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public: |
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CBufferedFile(FILE *fileIn, uint64_t nBufSize, uint64_t nRewindIn, int nTypeIn, int nVersionIn) : |
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nSrcPos(0), nReadPos(0), nReadLimit((uint64_t)(-1)), nRewind(nRewindIn), vchBuf(nBufSize, 0) |
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{ |
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src = fileIn; |
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nType = nTypeIn; |
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nVersion = nVersionIn; |
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} |
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~CBufferedFile() |
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{ |
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fclose(); |
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} |
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void fclose() |
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{ |
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if (src) { |
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::fclose(src); |
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src = NULL; |
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} |
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} |
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// check whether we're at the end of the source file
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bool eof() const { |
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return nReadPos == nSrcPos && feof(src); |
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} |
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// read a number of bytes
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CBufferedFile& read(char *pch, size_t nSize) { |
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if (nSize + nReadPos > nReadLimit) |
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throw std::ios_base::failure("Read attempted past buffer limit"); |
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if (nSize + nRewind > vchBuf.size()) |
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throw std::ios_base::failure("Read larger than buffer size"); |
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while (nSize > 0) { |
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if (nReadPos == nSrcPos) |
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Fill(); |
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unsigned int pos = nReadPos % vchBuf.size(); |
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size_t nNow = nSize; |
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if (nNow + pos > vchBuf.size()) |
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nNow = vchBuf.size() - pos; |
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if (nNow + nReadPos > nSrcPos) |
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nNow = nSrcPos - nReadPos; |
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memcpy(pch, &vchBuf[pos], nNow); |
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nReadPos += nNow; |
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pch += nNow; |
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nSize -= nNow; |
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} |
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return (*this); |
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} |
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// return the current reading position
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uint64_t GetPos() { |
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return nReadPos; |
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} |
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// rewind to a given reading position
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bool SetPos(uint64_t nPos) { |
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nReadPos = nPos; |
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if (nReadPos + nRewind < nSrcPos) { |
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nReadPos = nSrcPos - nRewind; |
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return false; |
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} else if (nReadPos > nSrcPos) { |
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nReadPos = nSrcPos; |
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return false; |
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} else { |
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return true; |
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} |
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} |
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bool Seek(uint64_t nPos) { |
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long nLongPos = nPos; |
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if (nPos != (uint64_t)nLongPos) |
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return false; |
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if (fseek(src, nLongPos, SEEK_SET)) |
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return false; |
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nLongPos = ftell(src); |
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nSrcPos = nLongPos; |
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nReadPos = nLongPos; |
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return true; |
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} |
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// prevent reading beyond a certain position
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// no argument removes the limit
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bool SetLimit(uint64_t nPos = (uint64_t)(-1)) { |
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if (nPos < nReadPos) |
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return false; |
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nReadLimit = nPos; |
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return true; |
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} |
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template<typename T> |
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CBufferedFile& operator>>(T& obj) { |
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// Unserialize from this stream
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::Unserialize(*this, obj, nType, nVersion); |
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return (*this); |
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} |
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|
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// search for a given byte in the stream, and remain positioned on it
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void FindByte(char ch) { |
||||
while (true) { |
||||
if (nReadPos == nSrcPos) |
||||
Fill(); |
||||
if (vchBuf[nReadPos % vchBuf.size()] == ch) |
||||
break; |
||||
nReadPos++; |
||||
} |
||||
} |
||||
}; |
||||
|
||||
#endif // BITCOIN_STREAMS_H
|
||||
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Reference in new issue