Remove duplicate include
[bitcoinplatinum.git] / src / compressor.h
blob015911484a1966189ca22bd365e45c9ccec39b66
1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2016 The Bitcoin Core developers
3 // Distributed under the MIT software license, see the accompanying
4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
6 #ifndef BITCOIN_COMPRESSOR_H
7 #define BITCOIN_COMPRESSOR_H
9 #include "primitives/transaction.h"
10 #include "script/script.h"
11 #include "serialize.h"
13 class CKeyID;
14 class CPubKey;
15 class CScriptID;
17 /** Compact serializer for scripts.
19 * It detects common cases and encodes them much more efficiently.
20 * 3 special cases are defined:
21 * * Pay to pubkey hash (encoded as 21 bytes)
22 * * Pay to script hash (encoded as 21 bytes)
23 * * Pay to pubkey starting with 0x02, 0x03 or 0x04 (encoded as 33 bytes)
25 * Other scripts up to 121 bytes require 1 byte + script length. Above
26 * that, scripts up to 16505 bytes require 2 bytes + script length.
28 class CScriptCompressor
30 private:
31 /**
32 * make this static for now (there are only 6 special scripts defined)
33 * this can potentially be extended together with a new nVersion for
34 * transactions, in which case this value becomes dependent on nVersion
35 * and nHeight of the enclosing transaction.
37 static const unsigned int nSpecialScripts = 6;
39 CScript &script;
40 protected:
41 /**
42 * These check for scripts for which a special case with a shorter encoding is defined.
43 * They are implemented separately from the CScript test, as these test for exact byte
44 * sequence correspondences, and are more strict. For example, IsToPubKey also verifies
45 * whether the public key is valid (as invalid ones cannot be represented in compressed
46 * form).
48 bool IsToKeyID(CKeyID &hash) const;
49 bool IsToScriptID(CScriptID &hash) const;
50 bool IsToPubKey(CPubKey &pubkey) const;
52 bool Compress(std::vector<unsigned char> &out) const;
53 unsigned int GetSpecialSize(unsigned int nSize) const;
54 bool Decompress(unsigned int nSize, const std::vector<unsigned char> &out);
55 public:
56 CScriptCompressor(CScript &scriptIn) : script(scriptIn) { }
58 template<typename Stream>
59 void Serialize(Stream &s) const {
60 std::vector<unsigned char> compr;
61 if (Compress(compr)) {
62 s << CFlatData(compr);
63 return;
65 unsigned int nSize = script.size() + nSpecialScripts;
66 s << VARINT(nSize);
67 s << CFlatData(script);
70 template<typename Stream>
71 void Unserialize(Stream &s) {
72 unsigned int nSize = 0;
73 s >> VARINT(nSize);
74 if (nSize < nSpecialScripts) {
75 std::vector<unsigned char> vch(GetSpecialSize(nSize), 0x00);
76 s >> REF(CFlatData(vch));
77 Decompress(nSize, vch);
78 return;
80 nSize -= nSpecialScripts;
81 if (nSize > MAX_SCRIPT_SIZE) {
82 // Overly long script, replace with a short invalid one
83 script << OP_RETURN;
84 s.ignore(nSize);
85 } else {
86 script.resize(nSize);
87 s >> REF(CFlatData(script));
92 /** wrapper for CTxOut that provides a more compact serialization */
93 class CTxOutCompressor
95 private:
96 CTxOut &txout;
98 public:
99 static uint64_t CompressAmount(uint64_t nAmount);
100 static uint64_t DecompressAmount(uint64_t nAmount);
102 CTxOutCompressor(CTxOut &txoutIn) : txout(txoutIn) { }
104 ADD_SERIALIZE_METHODS;
106 template <typename Stream, typename Operation>
107 inline void SerializationOp(Stream& s, Operation ser_action) {
108 if (!ser_action.ForRead()) {
109 uint64_t nVal = CompressAmount(txout.nValue);
110 READWRITE(VARINT(nVal));
111 } else {
112 uint64_t nVal = 0;
113 READWRITE(VARINT(nVal));
114 txout.nValue = DecompressAmount(nVal);
116 CScriptCompressor cscript(REF(txout.scriptPubKey));
117 READWRITE(cscript);
121 #endif // BITCOIN_COMPRESSOR_H