ContextCache Class Reference

A helper class for caching the active context blob to minimize database lookups. More...

#include <globalcontext.hh>

Public Member Functions
	ContextCache (ContextDatabase *db)
	Construct given a context database. More...
ContextDatabase *	getDatabase (void) const
	Retrieve the encapsulated database object.
void	allowSet (bool val)
	Toggle whether setContext() calls are ignored.
void	getContext (const Address &addr, uintm *buf) const
	Retrieve the context blob for the given address. More...
void	setContext (const Address &addr, int4 num, uintm mask, uintm value)
	Change the value of a context variable at the given address with no bound. More...
void	setContext (const Address &addr1, const Address &addr2, int4 num, uintm mask, uintm value)
	Change the value of a context variable across an explicit address range. More...

Private Attributes
ContextDatabase *	database
	The encapsulated context database.
bool	allowset
	If set to false, and setContext() call is dropped.
AddrSpace *	curspace
	Address space of the current valid range.
uintb	first
	Starting offset of the current valid range.
uintb	last
	Ending offset of the current valid range.
const uintm *	context
	The current cached context blob.

Detailed Description

A helper class for caching the active context blob to minimize database lookups.

This merely caches the last retrieved context blob ("array of words") and the range of addresses over which the blob is valid. It encapsulates the ContextDatabase itself and exposes a minimal interface (getContext() and setContext()).

Constructor & Destructor Documentation

ContextCache::ContextCache

(

ContextDatabase *

db

)

Construct given a context database.

Parameters

db	is the context database that will be encapsulated

Member Function Documentation

void ContextCache::getContext	(	const Address &	addr,
		uintm *	buf
	)		const

Retrieve the context blob for the given address.

Check if the address is in the current valid range. If it is, return the cached blob. Otherwise, make a call to the database and cache a new block and valid range.

Parameters

addr	is the given address
buf	is where the blob should be stored

References Address::getOffset(), and Address::getSpace().

void ContextCache::setContext	(	const Address &	addr,
		int4	num,
		uintm	mask,
		uintm	value
	)

Change the value of a context variable at the given address with no bound.

The context value is set starting at the given address and paints memory up to the next explicit change point.

Parameters

addr	is the given starting address
num	is the word index of the context variable
mask	is the mask delimiting the context variable
value	is the (already shifted) value to set

References Address::getOffset(), and Address::getSpace().

void ContextCache::setContext	(	const Address &	addr1,
		const Address &	addr2,
		int4	num,
		uintm	mask,
		uintm	value
	)

Change the value of a context variable across an explicit address range.

The context value is painted across the range. The context variable is marked as explicitly changing at the starting address of the range.

Parameters

addr1	is the starting address of the given range
addr2	is the ending address of the given range
num	is the word index of the context variable
mask	is the mask delimiting the context variable
value	is the (already shifted) value to set

References Address::getOffset(), and Address::getSpace().

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

• globalcontext.hh
• globalcontext.cc