Default asset resolution implementation used when no plugin implementation is provided. More...

#include <defaultResolver.h>

Inheritance diagram for ArDefaultResolver:

Static Public Member Functions
static AR_API void	SetDefaultSearchPath (const std::vector< std::string > &searchPath)
	Set the default search path that will be used during asset resolution.

Protected Member Functions
AR_API std::string	_CreateIdentifier (const std::string &assetPath, const ArResolvedPath &anchorAssetPath) const override
	Return an identifier for the asset at the given `assetPath`.

AR_API std::string	_CreateIdentifierForNewAsset (const std::string &assetPath, const ArResolvedPath &anchorAssetPath) const override
	Return an identifier for a new asset at the given `assetPath`.

AR_API ArResolvedPath	_Resolve (const std::string &assetPath) const override
	Return the resolved path for the given `assetPath` or an empty ArResolvedPath if no asset exists at that path.

AR_API ArResolvedPath	_ResolveForNewAsset (const std::string &assetPath) const override
	Return the resolved path for the given `assetPath` that may be used to create a new asset or an empty ArResolvedPath if such a path cannot be computed.

AR_API ArResolverContext	_CreateDefaultContext () const override
	Return a default ArResolverContext that may be bound to this resolver to resolve assets when no other context is explicitly specified.

AR_API ArResolverContext	_CreateDefaultContextForAsset (const std::string &assetPath) const override
	Creates a context that adds the directory containing `assetPath` as a first directory to be searched, when the resulting context is bound (.

AR_API ArResolverContext	_CreateContextFromString (const std::string &contextStr) const override
	Creates an ArDefaultResolverContext from `contextStr`.

AR_API bool	_IsContextDependentPath (const std::string &assetPath) const override
	Return true if the result of resolving the given `assetPath` may differ depending on the asset resolver context that is bound when Resolve is called, false otherwise.

AR_API ArTimestamp	_GetModificationTimestamp (const std::string &path, const ArResolvedPath &resolvedPath) const override
	Return an ArTimestamp representing the last time the asset at `assetPath` was modified.

AR_API std::shared_ptr< ArAsset >	_OpenAsset (const ArResolvedPath &resolvedPath) const override
	Return an ArAsset object for the asset located at `resolvedPath`.

AR_API std::shared_ptr< ArWritableAsset >	_OpenAssetForWrite (const ArResolvedPath &resolvedPath, WriteMode writeMode) const override
	Creates an ArFilesystemWriteableAsset for the asset at the given `resolvedPath`.

Protected Member Functions inherited from ArResolver
virtual AR_API bool	_IsRepositoryPath (const std::string &path) const

virtual AR_API void	_BindContext (const ArResolverContext &context, VtValue *bindingData)
	Bind the given `context` to this resolver.

virtual AR_API void	_UnbindContext (const ArResolverContext &context, VtValue *bindingData)
	Unbind the given `context` from this resolver.

virtual AR_API void	_RefreshContext (const ArResolverContext &context)
	Refresh any caches associated with the given context.

virtual AR_API ArResolverContext	_GetCurrentContext () const
	Return the currently bound context.

virtual AR_API std::string	_GetExtension (const std::string &assetPath) const
	Return the file extension for the given `assetPath`.

virtual AR_API ArAssetInfo	_GetAssetInfo (const std::string &assetPath, const ArResolvedPath &resolvedPath) const
	Return an ArAssetInfo populated with additional metadata (if any) about the asset at the given `assetPath`.

virtual AR_API bool	_CanWriteAssetToPath (const ArResolvedPath &resolvedPath, std::string *whyNot) const
	Return true if an asset may be written to the given `resolvedPath`, false otherwise.

virtual AR_API void	_BeginCacheScope (VtValue *cacheScopeData)
	Mark the start of a resolution caching scope.

virtual AR_API void	_EndCacheScope (VtValue *cacheScopeData)
	Mark the end of a resolution caching scope.

template<class ContextObj >
const ContextObj *	_GetCurrentContextObject () const
	Returns a pointer to the context object of type `ContextObj` from the last ArResolverContext that was bound via a call to BindContext, or `NULL` if no context object of that type exists.

Additional Inherited Members
Public Types inherited from ArResolver
enum class	WriteMode { Update = 0 , Replace }
	Enumeration of write modes for OpenAssetForWrite. More...

Public Member Functions inherited from ArResolver
	ArResolver (const ArResolver &)=delete

ArResolver &	operator= (const ArResolver &)=delete

AR_API std::string	CreateIdentifier (const std::string &assetPath, const ArResolvedPath &anchorAssetPath=ArResolvedPath()) const
	Returns an identifier for the asset specified by `assetPath`.

AR_API std::string	CreateIdentifierForNewAsset (const std::string &assetPath, const ArResolvedPath &anchorAssetPath=ArResolvedPath()) const
	Returns an identifier for a new asset specified by `assetPath`.

AR_API ArResolvedPath	Resolve (const std::string &assetPath) const
	Returns the resolved path for the asset identified by the given `assetPath` if it exists.

AR_API ArResolvedPath	ResolveForNewAsset (const std::string &assetPath) const
	Returns the resolved path for the given `assetPath` that may be used to create a new asset.

AR_API void	BindContext (const ArResolverContext &context, VtValue *bindingData)
	Binds the given context to this resolver.

AR_API void	UnbindContext (const ArResolverContext &context, VtValue *bindingData)
	Unbind the given context from this resolver.

AR_API ArResolverContext	CreateDefaultContext () const
	Return an ArResolverContext that may be bound to this resolver to resolve assets when no other context is explicitly specified.

AR_API ArResolverContext	CreateDefaultContextForAsset (const std::string &assetPath) const
	Return an ArResolverContext that may be bound to this resolver to resolve the asset located at `assetPath` or referenced by that asset when no other context is explicitly specified.

AR_API ArResolverContext	CreateContextFromString (const std::string &contextStr) const
	Return an ArResolverContext created from the primary ArResolver implementation using the given `contextStr`.

AR_API ArResolverContext	CreateContextFromString (const std::string &uriScheme, const std::string &contextStr) const
	Return an ArResolverContext created from the ArResolver registered for the given `uriScheme` using the given `contextStr`.

AR_API ArResolverContext	CreateContextFromStrings (const std::vector< std::pair< std::string, std::string > > &contextStrs) const
	Return an ArResolverContext created by combining the ArResolverContext objects created from the given `contextStrs`.

AR_API void	RefreshContext (const ArResolverContext &context)
	Refresh any caches associated with the given context.

AR_API ArResolverContext	GetCurrentContext () const
	Returns the asset resolver context currently bound in this thread.

AR_API bool	IsContextDependentPath (const std::string &assetPath) const
	Returns true if `assetPath` is a context-dependent path, false otherwise.

AR_API void	BeginCacheScope (VtValue *cacheScopeData)
	Mark the start of a resolution caching scope.

AR_API void	EndCacheScope (VtValue *cacheScopeData)
	Mark the end of a resolution caching scope.

AR_API bool	IsRepositoryPath (const std::string &path) const

AR_API std::string	GetExtension (const std::string &assetPath) const
	Returns the file extension for the given `assetPath`.

AR_API ArAssetInfo	GetAssetInfo (const std::string &assetPath, const ArResolvedPath &resolvedPath) const
	Returns an ArAssetInfo populated with additional metadata (if any) about the asset at the given `assetPath`.

AR_API ArTimestamp	GetModificationTimestamp (const std::string &assetPath, const ArResolvedPath &resolvedPath) const
	Returns an ArTimestamp representing the last time the asset at `assetPath` was modified.

AR_API std::shared_ptr< ArAsset >	OpenAsset (const ArResolvedPath &resolvedPath) const
	Returns an ArAsset object for the asset located at `resolvedPath`.

AR_API std::shared_ptr< ArWritableAsset >	OpenAssetForWrite (const ArResolvedPath &resolvedPath, WriteMode writeMode) const
	Returns an ArWritableAsset object for the asset located at `resolvedPath` using the specified `writeMode`.

AR_API bool	CanWriteAssetToPath (const ArResolvedPath &resolvedPath, std::string *whyNot=nullptr) const
	Returns true if an asset may be written to the given `resolvedPath`, false otherwise.

Detailed Description

Default asset resolution implementation used when no plugin implementation is provided.

In order to resolve assets specified by relative paths, this resolver implements a simple "search path" scheme. The resolver will anchor the relative path to a series of directories and return the first absolute path where the asset exists.

The first directory will always be the current working directory. The resolver will then examine the directories specified via the following mechanisms (in order):

The currently-bound ArDefaultResolverContext for the calling thread
ArDefaultResolver::SetDefaultSearchPath
The environment variable PXR_AR_DEFAULT_SEARCH_PATH. This is expected to be a list of directories delimited by the platform's standard path separator.

ArDefaultResolver supports creating an ArDefaultResolverContext via ArResolver::CreateContextFromString by passing a list of directories delimited by the platform's standard path separator.

Definition at line 64 of file defaultResolver.h.

Member Function Documentation

◆ _CreateContextFromString()

AR_API ArResolverContext _CreateContextFromString ( const std::string & contextStr ) const

overrideprotectedvirtual

Creates an ArDefaultResolverContext from contextStr.

This string is expected to be a list of directories delimited by the platform's standard path separator.

Reimplemented from ArResolver.

◆ _CreateDefaultContext()

AR_API ArResolverContext _CreateDefaultContext ( ) const

overrideprotectedvirtual

Return a default ArResolverContext that may be bound to this resolver to resolve assets when no other context is explicitly specified.

When CreateDefaultContext is called on the configured asset resolver, Ar will call this method on the primary resolver and all URI/IRI resolvers and merge the results into a single ArResolverContext that will be returned to the consumer.

This function should not automatically bind this context, but should create one that may be used later.

The default implementation returns a default-constructed ArResolverContext.

Example uses:

UsdStage will call CreateDefaultContext when creating a new stage with an anonymous root layer and without a given context. The returned context will be bound when resolving asset paths on that stage.

Reimplemented from ArResolver.

◆ _CreateDefaultContextForAsset()

AR_API ArResolverContext _CreateDefaultContextForAsset ( const std::string & assetPath ) const

overrideprotectedvirtual

Creates a context that adds the directory containing assetPath as a first directory to be searched, when the resulting context is bound (.

See also: ArResolverContextBinder).

If assetPath is empty, returns an empty context; otherwise, if assetPath is not an absolute filesystem path, it will first be anchored to the process's current working directory.

Reimplemented from ArResolver.

◆ _CreateIdentifier()

AR_API std::string _CreateIdentifier	(	const std::string &	assetPath,
		const ArResolvedPath &	anchorAssetPath
	)		const

overrideprotectedvirtual

Return an identifier for the asset at the given assetPath.

See Identifiers for more information.

If anchorAssetPath is non-empty, it should be used as the anchoring asset if assetPath is relative. For example, for a filesystem-based implementation _CreateIdentifier might return:

_CreateIdentifier( /* assetPath = ‍/ "/abs/path/to/model.usd", / anchorAssetPath = *‍/ ArResolvedPath("/abs/path/to/shot.usd")) => "/abs/path/to/model.usd"

_CreateIdentifier( /* assetPath = ‍/ "relative/model.usd", / anchorAssetPath = *‍/ ArResolvedPath("/abs/path/to/shot.usd")) => "/abs/path/to/relative/model.usd"

Identifiers may be compared to determine if given paths refer to the same asset, so implementations should take care to canonicalize and normalize the returned identifier to a consistent format.

If either assetPath or anchorAssetPath have a URI/IRI scheme, this function will be called on the resolver associated with that URI/IRI scheme, if any.

Example uses:

When opening a layer via SdfLayer::FindOrOpen or Find, CreateIdentifier will be called with the asset path given to those functions and no anchoring asset path. The result will be used as the layer's identifier.
When processing composition arcs that refer to other layers, this function will be called with the asset path of the referenced layer and the resolved path of the layer where the composition arc was authored. The result will be passed to SdfLayer::FindOrOpen to open the referenced layer.

Implements ArResolver.

◆ _CreateIdentifierForNewAsset()

AR_API std::string _CreateIdentifierForNewAsset	(	const std::string &	assetPath,
		const ArResolvedPath &	anchorAssetPath
	)		const

overrideprotectedvirtual

Return an identifier for a new asset at the given assetPath.

This is similar to _CreateIdentifier but is used to create identifiers for assets that may not exist yet and are being created.

Example uses:

When creating a new layer via SdfLayer::CreateNew, CreateIdentifierForNewAsset will be called with the asset path given to the function. The result will be used as the new layer's identifier.

Implements ArResolver.

◆ _GetModificationTimestamp()

AR_API ArTimestamp _GetModificationTimestamp	(	const std::string &	assetPath,
		const ArResolvedPath &	resolvedPath
	)		const

overrideprotectedvirtual

Return an ArTimestamp representing the last time the asset at assetPath was modified.

resolvedPath is the resolved path computed for the given assetPath. If a timestamp cannot be retrieved, return an invalid ArTimestamp.

The default implementation returns an invalid ArTimestamp.

Example uses:

SdfLayer will call GetModificationTimestamp when opening a layer and store the returned timestamp. When SdfLayer::Reload is called on that layer, this method will be called again. If the returned timestamp differs from the stored timestamp, or if it is invalid, the layer will be reloaded.

Reimplemented from ArResolver.

◆ _IsContextDependentPath()

AR_API bool _IsContextDependentPath ( const std::string & assetPath ) const

overrideprotectedvirtual

Return true if the result of resolving the given assetPath may differ depending on the asset resolver context that is bound when Resolve is called, false otherwise.

The default implementation returns false.

Example uses:

SdfLayer will call this function to check if the identifier given to SdfLayer::Find or SdfLayer::FindOrOpen is context-dependent. If it is and a layer exists with the same identifier, SdfLayer can return it without resolving the identifier. If it is not, SdfLayer must resolve the identifier and search for a layer with the same resolved path, even if a layer exists with the same identifier.

Reimplemented from ArResolver.

◆ _OpenAsset()

AR_API std::shared_ptr< ArAsset > _OpenAsset ( const ArResolvedPath & resolvedPath ) const

overrideprotectedvirtual

Return an ArAsset object for the asset located at resolvedPath.

Return an invalid std::shared_ptr if object could not be created (for example, if the asset at the given path could not be opened).

Note that clients may still be using the data associated with this object even after the last shared_ptr has been destroyed. For example, a client may have created a memory mapping using the FILE* presented in the ArAsset object; this would preclude truncating or overwriting any of the contents of that file.

Implements ArResolver.

◆ _OpenAssetForWrite()

AR_API std::shared_ptr< ArWritableAsset > _OpenAssetForWrite	(	const ArResolvedPath &	resolvedPath,
		WriteMode	writeMode
	)		const

overrideprotectedvirtual

Creates an ArFilesystemWriteableAsset for the asset at the given resolvedPath.

Implements ArResolver.

◆ _Resolve()

AR_API ArResolvedPath _Resolve ( const std::string & assetPath ) const

overrideprotectedvirtual

Return the resolved path for the given assetPath or an empty ArResolvedPath if no asset exists at that path.

Implements ArResolver.

◆ _ResolveForNewAsset()

AR_API ArResolvedPath _ResolveForNewAsset ( const std::string & assetPath ) const

overrideprotectedvirtual

Return the resolved path for the given assetPath that may be used to create a new asset or an empty ArResolvedPath if such a path cannot be computed.

Implements ArResolver.

◆ SetDefaultSearchPath()

static AR_API void SetDefaultSearchPath ( const std::vector< std::string > & searchPath )

static

Set the default search path that will be used during asset resolution.

This must be called before the first call to ArGetResolver. The specified paths will be searched in addition to, and before paths specified via the environment variable PXR_AR_DEFAULT_SEARCH_PATH

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

pxr/usd/ar/defaultResolver.h

Static Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ _CreateContextFromString()

◆ _CreateDefaultContext()

◆ _CreateDefaultContextForAsset()

◆ _CreateIdentifier()

◆ _CreateIdentifierForNewAsset()

◆ _GetModificationTimestamp()

◆ _IsContextDependentPath()

◆ _OpenAsset()

◆ _OpenAssetForWrite()

◆ _Resolve()

◆ _ResolveForNewAsset()

◆ SetDefaultSearchPath()