Panda3D
Public Member Functions | Static Public Member Functions | Public Attributes
BamCache Class Reference

This class maintains a cache of Bam and/or Txo objects generated from model files and texture images (as well as possibly other kinds of loadable objects that can be stored in bam file format). More...

#include "bamCache.h"

List of all members.

Public Member Functions

void consider_flush_index ()
 Flushes the index if enough time has elapsed since the index was last flushed.
void flush_index ()
 Ensures the index is written to disk.
bool get_active () const
 Returns true if the BamCache is currently active, false if it is not.
bool get_cache_compressed_textures () const
 Returns whether compressed texture files will be stored in the cache, as compressed txo files.
int get_cache_max_kbytes () const
 Returns the maximum size, in kilobytes, which the cache is allowed to grow to.
bool get_cache_models () const
 Returns whether model files (e.g.
bool get_cache_textures () const
 Returns whether texture files (e.g.
int get_flush_time () const
 Returns the time in seconds between automatic flushes of the cache index.
bool get_read_only () const
 Returns true if the cache is in read-only mode.
Filename get_root () const
 Returns the current root pathname of the cache.
 PT (BamCacheRecord) lookup(const Filename &source_filename
void set_active (bool flag)
 Changes the state of the active flag.
void set_cache_compressed_textures (bool flag)
 Indicates whether compressed texture files will be stored in the cache, as compressed txo files.
void set_cache_max_kbytes (int max_kbytes)
 Specifies the maximum size, in kilobytes, which the cache is allowed to grow to.
void set_cache_models (bool flag)
 Indicates whether model files (e.g.
void set_cache_textures (bool flag)
 Indicates whether texture files will be stored in the cache, as uncompressed txo files.
void set_flush_time (int flush_time)
 Specifies the time in seconds between automatic flushes of the cache index.
void set_read_only (bool ro)
 Can be used to put the cache in read-only mode, or take it out of read-only mode.
void set_root (const Filename &root)
 Changes the current root pathname of the cache.
bool store (BamCacheRecord *record)
 Flushes a cache entry to disk.

Static Public Member Functions

static BamCacheget_global_ptr ()
 Returns a pointer to the global BamCache object, which is used automatically by the ModelPool and TexturePool.

Public Attributes

const string & cache_extension

Detailed Description

This class maintains a cache of Bam and/or Txo objects generated from model files and texture images (as well as possibly other kinds of loadable objects that can be stored in bam file format).

This class also maintains a persistent index that lists all of the cached objects (see BamCacheIndex). We go through some considerable effort to make sure this index gets saved correctly to disk, even in the presence of multiple different processes writing to the same index, and without relying too heavily on low-level os-provided file locks (which work poorly with C++ iostreams).

Definition at line 47 of file bamCache.h.


Member Function Documentation

Flushes the index if enough time has elapsed since the index was last flushed.

Definition at line 315 of file bamCache.cxx.

References flush_index().

Referenced by GraphicsEngine::render_frame(), and store().

bool BamCache::get_active ( ) const [inline]

Returns true if the BamCache is currently active, false if it is not.

"active" means that the cache should be consulted automatically on loads, "not active" means that objects should be loaded directly without consulting the cache.

This represents the global flag. Also see the individual cache_models, cache_textures, cache_compressed_textures flags.

Definition at line 48 of file bamCache.I.

bool BamCache::get_cache_compressed_textures ( ) const [inline]

Returns whether compressed texture files will be stored in the cache, as compressed txo files.

See set_cache_compressed_textures().

This also returns false if get_active() is false.

Definition at line 140 of file bamCache.I.

Referenced by Texture::do_reload_ram_image().

int BamCache::get_cache_max_kbytes ( ) const [inline]

Returns the maximum size, in kilobytes, which the cache is allowed to grow to.

See set_cache_max_kbytes().

Definition at line 210 of file bamCache.I.

bool BamCache::get_cache_models ( ) const [inline]

Returns whether model files (e.g.

egg files and bam files) will be stored in the cache, as bam files.

This also returns false if get_active() is false.

Definition at line 74 of file bamCache.I.

bool BamCache::get_cache_textures ( ) const [inline]

Returns whether texture files (e.g.

egg files and bam files) will be stored in the cache, as txo files.

This also returns false if get_active() is false.

Definition at line 100 of file bamCache.I.

Referenced by Texture::do_reload_ram_image().

int BamCache::get_flush_time ( ) const [inline]

Returns the time in seconds between automatic flushes of the cache index.

Definition at line 176 of file bamCache.I.

BamCache * BamCache::get_global_ptr ( ) [inline, static]
bool BamCache::get_read_only ( ) const [inline]

Returns true if the cache is in read-only mode.

Normally, the cache starts in read-write mode. It can put itself into read-only mode automatically if it discovers that it does not have write access to the cache.

Definition at line 240 of file bamCache.I.

Filename BamCache::get_root ( ) const [inline]

Returns the current root pathname of the cache.

See set_root().

Definition at line 152 of file bamCache.I.

void BamCache::set_active ( bool  active) [inline]

Changes the state of the active flag.

"active" means that the cache should be consulted automatically on loads, "not active" means that objects should be loaded directly without consulting the cache.

This represents the global flag. Also see the individual cache_models, cache_textures, cache_compressed_textures flags.

Definition at line 29 of file bamCache.I.

void BamCache::set_cache_compressed_textures ( bool  flag) [inline]

Indicates whether compressed texture files will be stored in the cache, as compressed txo files.

The compressed data may either be generated in-CPU, via the squish library, or it may be extracted from the GSG after the texture has been loaded.

This may be set in conjunction with set_cache_textures(), or independently of it. If set_cache_textures() is true and this is false, all textures will be cached in their uncompressed form. If set_cache_textures() is false and this is true, only compressed textures will be cached, and they will be cached in their compressed form. If both are true, all textures will be cached, in their uncompressed or compressed form appropriately.

Definition at line 125 of file bamCache.I.

void BamCache::set_cache_max_kbytes ( int  max_kbytes) [inline]

Specifies the maximum size, in kilobytes, which the cache is allowed to grow to.

If a newly cached file would exceed this size, an older file is removed from the cache.

Note that in the case of multiple different processes simultaneously operating on the same cache directory, the actual cache size may slightly exceed this value from time to time due to latency in checking between the processes.

Definition at line 196 of file bamCache.I.

void BamCache::set_cache_models ( bool  flag) [inline]

Indicates whether model files (e.g.

egg files and bam files) will be stored in the cache, as bam files.

Definition at line 60 of file bamCache.I.

void BamCache::set_cache_textures ( bool  flag) [inline]

Indicates whether texture files will be stored in the cache, as uncompressed txo files.

Definition at line 86 of file bamCache.I.

void BamCache::set_flush_time ( int  flush_time) [inline]

Specifies the time in seconds between automatic flushes of the cache index.

Definition at line 164 of file bamCache.I.

void BamCache::set_read_only ( bool  ro) [inline]

Can be used to put the cache in read-only mode, or take it out of read-only mode.

Note that if you put it into read-write mode, and it discovers that it does not have write access, it will put itself right back into read-only mode.

Definition at line 225 of file bamCache.I.

void BamCache::set_root ( const Filename root)

Changes the current root pathname of the cache.

This specifies where the cache files are stored on disk. This should name a directory that is on a disk local to the machine (not on a network-mounted disk), for instance, /tmp/panda-cache or /c/panda-cache.

If the directory does not already exist, it will be created as a result of this call.

Definition at line 116 of file bamCache.cxx.

References flush_index(), get_global_ptr(), VirtualFileSystem::is_directory(), and VirtualFileSystem::make_directory_full().

bool BamCache::store ( BamCacheRecord record)

The documentation for this class was generated from the following files:
 All Classes Functions Variables Enumerations