CScriptCompressor Class Reference

Compact serializer for scripts. More...

#include <compressor.h>

Collaboration diagram for CScriptCompressor:

Public Member Functions
	CScriptCompressor (CScript &scriptIn)
template<typename Stream >
void	Serialize (Stream &s) const
template<typename Stream >
void	Unserialize (Stream &s)

Protected Member Functions
bool	IsToKeyID (CKeyID &hash) const
	These check for scripts for which a special case with a shorter encoding is defined. More...
bool	IsToScriptID (CScriptID &hash) const
bool	IsToPubKey (CPubKey &pubkey) const
bool	Compress (std::vector< unsigned char > &out) const
unsigned int	GetSpecialSize (unsigned int nSize) const
bool	Decompress (unsigned int nSize, const std::vector< unsigned char > &out)

Private Attributes
CScript &	script

Static Private Attributes
static const unsigned int	nSpecialScripts = 6
	make this static for now (there are only 6 special scripts defined) this can potentially be extended together with a new nVersion for transactions, in which case this value becomes dependent on nVersion and nHeight of the enclosing transaction. More...

Detailed Description

Compact serializer for scripts.

It detects common cases and encodes them much more efficiently. 3 special cases are defined:

• Pay to pubkey hash (encoded as 21 bytes)
• Pay to script hash (encoded as 21 bytes)
• Pay to pubkey starting with 0x02, 0x03 or 0x04 (encoded as 33 bytes)

Other scripts up to 121 bytes require 1 byte + script length. Above that, scripts up to 16505 bytes require 2 bytes + script length.

Definition at line 28 of file compressor.h.

Constructor & Destructor Documentation

CScriptCompressor()

CScriptCompressor::CScriptCompressor ( CScript &  scriptIn )

inlineexplicit

Definition at line 56 of file compressor.h.

Member Function Documentation

Compress()

bool CScriptCompressor::Compress ( std::vector< unsigned char > &  out ) const

protected

Definition at line 48 of file compressor.cpp.

References IsToKeyID(), IsToPubKey(), IsToScriptID(), and memcpy().

Referenced by Serialize().

Decompress()

bool CScriptCompressor::Decompress ( unsigned int  nSize, const std::vector< unsigned char > &  out  )

protected

Definition at line 88 of file compressor.cpp.

References prevector< N, T, Size, Diff >::begin(), prevector< N, T, Size, Diff >::data(), memcpy(), OP_CHECKSIG, OP_DUP, OP_EQUAL, OP_EQUALVERIFY, OP_HASH160, prevector< N, T, Size, Diff >::resize(), and script.

Referenced by Unserialize().

GetSpecialSize()

unsigned int CScriptCompressor::GetSpecialSize ( unsigned int  nSize ) const

protected

Definition at line 79 of file compressor.cpp.

Referenced by Unserialize().

IsToKeyID()

bool CScriptCompressor::IsToKeyID ( CKeyID &  hash ) const

protected

These check for scripts for which a special case with a shorter encoding is defined.

They are implemented separately from the CScript test, as these test for exact byte sequence correspondences, and are more strict. For example, IsToPubKey also verifies whether the public key is valid (as invalid ones cannot be represented in compressed form).

Definition at line 12 of file compressor.cpp.

References memcpy(), OP_CHECKSIG, OP_DUP, OP_EQUALVERIFY, OP_HASH160, script, and prevector< N, T, Size, Diff >::size().

Referenced by Compress().

IsToPubKey()

bool CScriptCompressor::IsToPubKey ( CPubKey &  pubkey ) const

protected

Definition at line 33 of file compressor.cpp.

References CPubKey::IsFullyValid(), OP_CHECKSIG, script, CPubKey::Set(), and prevector< N, T, Size, Diff >::size().

Referenced by Compress().

IsToScriptID()

bool CScriptCompressor::IsToScriptID ( CScriptID &  hash ) const

protected

Definition at line 23 of file compressor.cpp.

References memcpy(), OP_EQUAL, OP_HASH160, script, and prevector< N, T, Size, Diff >::size().

Referenced by Compress().

Serialize()

template<typename Stream >

void CScriptCompressor::Serialize ( Stream &  s ) const

inline

Definition at line 59 of file compressor.h.

References Compress(), nSpecialScripts, script, prevector< N, T, Size, Diff >::size(), and VARINT.

Unserialize()

template<typename Stream >

void CScriptCompressor::Unserialize ( Stream &  s )

inline

Definition at line 71 of file compressor.h.

References Decompress(), GetSpecialSize(), MAX_SCRIPT_SIZE, nSpecialScripts, OP_RETURN, REF(), prevector< N, T, Size, Diff >::resize(), script, and VARINT.

Member Data Documentation

nSpecialScripts

const unsigned int CScriptCompressor::nSpecialScripts = 6

staticprivate

make this static for now (there are only 6 special scripts defined) this can potentially be extended together with a new nVersion for transactions, in which case this value becomes dependent on nVersion and nHeight of the enclosing transaction.

Definition at line 37 of file compressor.h.

Referenced by Serialize(), and Unserialize().

script

CScript& CScriptCompressor::script

private

Definition at line 39 of file compressor.h.

Referenced by Decompress(), IsToKeyID(), IsToPubKey(), IsToScriptID(), Serialize(), and Unserialize().

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The documentation for this class was generated from the following files:

• src/compressor.h
• src/compressor.cpp