Panda3D
Public Member Functions | Static Public Member Functions | Public Attributes | List of all members
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...

Public Member Functions

 __init__ ()
 
 considerFlushIndex ()
 Flushes the index if enough time has elapsed since the index was last flushed. More...
 
 flushIndex ()
 Ensures the index is written to disk. More...
 
bool getActive ()
 Returns true if the BamCache is currently active, false if it is not. More...
 
bool getCacheCompiledShaders ()
 Returns whether compiled shader programs will be stored in the cache, as binary .txo files. More...
 
bool getCacheCompressedTextures ()
 Returns whether compressed texture files will be stored in the cache, as compressed txo files. More...
 
int getCacheMaxKbytes ()
 Returns the maximum size, in kilobytes, which the cache is allowed to grow to. More...
 
bool getCacheModels ()
 Returns whether model files (e.g. More...
 
bool getCacheTextures ()
 Returns whether texture files (e.g. More...
 
int getFlushTime ()
 Returns the time in seconds between automatic flushes of the cache index. More...
 
bool getReadOnly ()
 Returns true if the cache is in read-only mode. More...
 
Filename getRoot ()
 Returns the current root pathname of the cache. More...
 
 listIndex (Ostream out, int indent_level)
 Writes the contents of the index to standard output. More...
 
BamCacheRecord lookup (const Filename source_filename, str cache_extension)
 Looks up a file in the cache. More...
 
 setActive (bool flag)
 Changes the state of the active flag. More...
 
 setCacheCompiledShaders (bool flag)
 Indicates whether compiled shader programs will be stored in the cache, as binary .sho files. More...
 
 setCacheCompressedTextures (bool flag)
 Indicates whether compressed texture files will be stored in the cache, as compressed txo files. More...
 
 setCacheMaxKbytes (int max_kbytes)
 Specifies the maximum size, in kilobytes, which the cache is allowed to grow to. More...
 
 setCacheModels (bool flag)
 Indicates whether model files (e.g. More...
 
 setCacheTextures (bool flag)
 Indicates whether texture files will be stored in the cache, as uncompressed txo files. More...
 
 setFlushTime (int flush_time)
 Specifies the time in seconds between automatic flushes of the cache index. More...
 
 setReadOnly (bool ro)
 Can be used to put the cache in read-only mode, or take it out of read-only mode. More...
 
 setRoot (const Filename root)
 Changes the current root pathname of the cache. More...
 
bool store (BamCacheRecord record)
 Flushes a cache entry to disk. More...
 

Static Public Member Functions

static considerFlushGlobalIndex ()
 If there is a global BamCache object, calls consider_flush_index() on it. More...
 
static flushGlobalIndex ()
 If there is a global BamCache object, calls flush_index() on it. More...
 
static BamCache getGlobalPtr ()
 Returns a pointer to the global BamCache object, which is used automatically by the ModelPool and TexturePool. More...
 

Public Attributes

bool active
 Returns true if the BamCache is currently active, false if it is not. More...
 
bool cache_compiled_shaders
 Returns whether compiled shader programs will be stored in the cache, as binary .txo files. More...
 
bool cache_compressed_textures
 Returns whether compressed texture files will be stored in the cache, as compressed txo files. More...
 
int cache_max_kbytes
 Returns the maximum size, in kilobytes, which the cache is allowed to grow to. More...
 
bool cache_models
 Returns whether model files (e.g. More...
 
bool cache_textures
 Returns whether texture files (e.g. More...
 
int flush_time
 Returns the time in seconds between automatic flushes of the cache index. More...
 
bool read_only
 Returns true if the cache is in read-only mode. More...
 
Filename root
 Returns the current root pathname of the cache. More...
 

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).

Member Function Documentation

◆ __init__()

__init__ ( )

◆ considerFlushGlobalIndex()

static considerFlushGlobalIndex ( )
static

If there is a global BamCache object, calls consider_flush_index() on it.

◆ considerFlushIndex()

considerFlushIndex ( )

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

◆ flushGlobalIndex()

static flushGlobalIndex ( )
static

If there is a global BamCache object, calls flush_index() on it.

◆ flushIndex()

flushIndex ( )

Ensures the index is written to disk.

◆ getActive()

bool getActive ( )

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.

◆ getCacheCompiledShaders()

bool getCacheCompiledShaders ( )

Returns whether compiled shader programs will be stored in the cache, as binary .txo files.

See set_cache_compiled_shaders().

This also returns false if get_active() is false.

◆ getCacheCompressedTextures()

bool getCacheCompressedTextures ( )

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.

◆ getCacheMaxKbytes()

int getCacheMaxKbytes ( )

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

See set_cache_max_kbytes().

◆ getCacheModels()

bool getCacheModels ( )

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.

◆ getCacheTextures()

bool getCacheTextures ( )

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.

◆ getFlushTime()

int getFlushTime ( )

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

◆ getGlobalPtr()

static BamCache getGlobalPtr ( )
static

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

◆ getReadOnly()

bool getReadOnly ( )

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.

◆ getRoot()

Filename getRoot ( )

Returns the current root pathname of the cache.

See set_root().

◆ listIndex()

listIndex ( Ostream  out,
int  indent_level 
)

Writes the contents of the index to standard output.

◆ lookup()

BamCacheRecord lookup ( const Filename  source_filename,
str  cache_extension 
)

Looks up a file in the cache.

If the file is cacheable, then regardless of whether the file is found in the cache or not, this returns a BamCacheRecord. On the other hand, if the file cannot be cached, returns NULL.

If record->has_data() returns true, then the file was found in the cache, and you may call record->extract_data() to get the object. If record->has_data() returns false, then the file was not found in the cache or the cache was stale; and you should reload the source file (calling record->add_dependent_file() for each file loaded, including the original source file), and then call record->set_data() to record the resulting loaded object; and finally, you should call store() to write the cached record to disk.

◆ setActive()

setActive ( bool  flag)

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.

◆ setCacheCompiledShaders()

setCacheCompiledShaders ( bool  flag)

Indicates whether compiled shader programs will be stored in the cache, as binary .sho files.

This may not be supported by all shader languages or graphics renderers.

◆ setCacheCompressedTextures()

setCacheCompressedTextures ( bool  flag)

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.

◆ setCacheMaxKbytes()

setCacheMaxKbytes ( int  max_kbytes)

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.

◆ setCacheModels()

setCacheModels ( bool  flag)

Indicates whether model files (e.g.

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

◆ setCacheTextures()

setCacheTextures ( bool  flag)

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

◆ setFlushTime()

setFlushTime ( int  flush_time)

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

◆ setReadOnly()

setReadOnly ( bool  ro)

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.

◆ setRoot()

setRoot ( 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.

◆ store()

bool store ( BamCacheRecord  record)

Flushes a cache entry to disk.

You must have retrieved the cache record via a prior call to lookup(), and then stored the data via record->set_data(). Returns true on success, false on failure.

Member Data Documentation

◆ active

bool active

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.

◆ cache_compiled_shaders

bool cache_compiled_shaders

Returns whether compiled shader programs will be stored in the cache, as binary .txo files.

See set_cache_compiled_shaders().

This also returns false if get_active() is false.

◆ cache_compressed_textures

bool cache_compressed_textures

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.

◆ cache_max_kbytes

int cache_max_kbytes

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

See set_cache_max_kbytes().

◆ cache_models

bool cache_models

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.

◆ cache_textures

bool cache_textures

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.

◆ flush_time

int flush_time

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

◆ read_only

bool read_only

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.

◆ root

Filename root

Returns the current root pathname of the cache.

See set_root().