Copyright ©1995 by NeXT Computer, Inc. All Rights Reserved.
| IXFileFinder |
| Inherits From: | Object | |
| Conforms To: | IXBlockAndStoreAccess IXNameAndFileAccess IXFileFinderConfiguration IXFileFinderQueryAndUpdate NXReference (Mach Kit) | |
| Declared In: | indexing/IXFileFinder.h |
| Class Description |
| IXFileFinder answers queries against file attributes over a file system subtree, and can maintain indexes to improve query performance. IXFileFinder manipulates instances of the IXFileRecord class as proxies for the actual files; queries return IXPostingLists containing IXFileRecords representing the selected files. When used with an IXStore or IXStoreFile, IXFileFinder uses a private instance of the IXRecordManager class to store and index the IXFileRecords; this permits the efficient resolution of many queries without requiring the file system subtree to be scanned every time a query is performed.
IXFileFinder is completely thread-safe; it supports multiple asynchronous queries by programmer-supplied threads without conflict, and also provides an asynchronous index updating mechanism managed by a single, private background thread. The functionality of IXFileFinder is primarily described in its two protocol specifications, IXFileFinderConfiguration and IXFileFinderQueryAndUpdate, which anticipate its use with NEXTSTEP's Distributed Object facility. This class specification documents only the initialization methods. |
| Instance Variables |
| unsigned int references;
List *attributeParsers; id recordManager; NXHashTable *ignoredNames; NXHashTable *ignoredTypes; char *rootPath; unsigned int commitDelay; struct { |
| references | The reference count. | |
| attributeParsers | A List of IXAttributeParsers used to parse files. | |
| recordManager | The object that manages the file records. | |
| ignoredNames | The names of files that are ignored by the IXFileFinder. | |
| ignoredTypes | The types of files that are ignored by the IXFileFinder. | |
| rootPath | The root directory of the IXFileFinder. This is considered the base of the subtree for which queries can be made. | |
| commitDelay | The delay in seconds between consecutive transaction commitments during index update. |
| booleanOptions.crossesDeviceChanges |
| YES if the IXFileFinder addresses files on physical devices other than the one its primary directory is on. NO by default. |
| booleanOptions.followsSymbolicLinks |
| YES if the IXFileFinder follows symbolic links. NO by default. |
| booleanOptions.generatesDescriptions |
| YES if the IXFileFinder automatically generates descriptions for IXFileRecords from the file contents. NO by default. |
| booleanOptions.updatesAutomatically |
| YES if the IXFileFinder automatically queues out-of-date files for indexing when a query is performed. YES by default. |
| booleanOptions.scansForModifiedFiles |
| YES if the IXFileFinder scans for modified files when a query is performed. YES by default. |
| booleanOptions.removesAutomatically |
| YES if the IXFileFinder scans for deleted files when updating, removing their proxies from the index. YES by default. |
| Adopted Protocols |
| IXBlockAndStoreAccess |  initInStore: |
| initFromBlock:inStore: + freeFromBlock:inStore: freeFromStore getBlock:andStore: |
| IXNameAndFileAccess | initWithName:inFile: |
| initFromName:inFile:forWriting: + freeFromName:inFile: freeFromStore getName:andFile: |
| IXFileFinderConfiguration | setAttributeParsers: |
| getAttributeParsers: setCrossesDeviceChanges: crossesDeviceChanges setFollowsSymbolicLinks: followsSymbolicLinks setGeneratesDescriptions: generatesDescriptions setIgnoredNames: ignoredNames setIgnoredTypes: ignoredTypes setScansForModifiedFiles: scansForModifiedFiles setUpdatesAutomatically: updatesAutomatically |
| IXFileFinderQueryAndUpdate | rootPath |
| recordManager performQuery:atPath:forSender: stopQueryForSender: updateIndexAtPath: isUpdating suspendUpdating resumeUpdating clean reset |
| NXReference | references |
| addReference free |
| Method Types |
| Initializing an IXFileFinder | initInStore:atPath: |
| initFromBlock:inStore:atPath: initWithName:inFile:atPath: initWithName:inFile:forWriting:atPath: |
| Instance Methods |
| initFromBlock:inStore: |
| initFromBlock:(unsigned int)aHandle inStore:(IXStore *)aStore |
| Initializes a newly allocated IXFileFinder as initFromBlock:inStore:atPath: with a path argument of NULL. This method is useful for opening an IXFileFinder whose root directory hasn't changed, which is usually the case.
See also: |
| initFromBlock:inStore:atPath: |
| initFromBlock:(unsigned int)aHandle |
| inStore:(IXStore *)aStore atPath:(const char *)path |
| Initializes a newly allocated IXFileFinder by opening it from data stored in the block of aStore identified by aHandle. This data should have been created by a previous instance of IXFileFinder. The IXFileFinder's root path is reset to path; it will search for files within the subtree rooted at that directory. path may be an absolute or relative pathname. If path is NULL, the root path remains unchanged from its previous value. The root path may not be changed after initialization. Returns self.
This is the designated initializer for opening a pre-existing IXFileFinder with the IXBlockAndStoreAccess protocol. See also: |
| initFromName:inFile:forWriting: |
| initFromName:(const char *)aName |
| inFile:(const char *)filename forWriting:(BOOL)flag |
| Initializes a newly allocated IXFileFinder as initFromName:inFile:forWriting:atPath: with a path argument of NULL. This method is useful for opening an IXFileFinder whose root directory hasn't changed, which is usually the case.
See also: |
| initFromName:inFile:forWriting:atPath: |
| initFromName:(const char *)aName |
| inFile:(const char *)filename forWriting:(BOOL)flag atPath:(const char *)path |
| Initializes a newly allocated IXFileFinder by opening it from data stored under aName in filename by a previous instance. The IXFileFinder's root path is reset to path; it will search for files within the subtree rooted at that directory. path can be an absolute or relative pathname, or it can be NULL, in which case the IXFileFinder's root path remains unchanged. The root path may not subsequently be changed unless the IXFileFinder is freed and then reopened. If flag is YES, filename is opened for reading and writing, and the IXFileFinder is initialized to build and update its index; if flag is NO, filename is opened for reading only. Returns self if successful, or nil if flag is YES and filename can't be written or created.
An IXFileFinder opened for reading only can be modified; however, the changes occur only in memory, and are never written to disk. This can be useful for keeping an index up-to-date until the application terminates, without affecting the original file. This is the designated initializer for opening a pre-existing IXFileFinder with the IXNameAndFileAccess protocol. Note that the underlying IXStoreFile is opened by the IXFileFinder when this method is used, and that it will be closed when the IXFileFinder is freed. See also: |
| initInStore: |
| initInStore:(IXStore *)aStore |
| Initializes a newly allocated IXFileFinder as initInStore:atPath: with a path argument of NULL.
See also: |
| initInStore:atPath: |
| initInStore:(IXStore *)aStore atPath:(const char *)path |
| Initializes a newly allocated IXFileFinder in aStore, to search for files in the subtree rooted at the directory named path. path is considered the root path for the IXFileFinder, and can be an absolute or relative pathname. If path is NULL, the program's working directory is used. The root path may not be changed after initialization. If aStore is nil, then the IXFileFinder won't attempt to maintain indexes on file attributes using IXRecordManager. This doesn't affect query semantics in any way; an IXFileFinder initialized without an IXStore will return the same query results as an IXFileFinder initialized with an IXStore. The presence or absence of an IXStore merely affects query performance. Returns self.
This is the designated initializer for creating new IXFileFinders with the IXBlockAndStoreAccess protocol. See also: |
| initWithName:inFile: |
| initWithName:(const char *)aName inFile:(const char *)filename |
| Initializes a newly allocated IXFileFinder as initWithName:inFile:atPath:, with a path argument of NULL.
See also: |
| initWithName:inFile:atPath: |
| initWithName:(const char *)aName |
| inFile:(const char *)filename atPath:(const char *)path |
| Initializes the IXFileFinder as a store file client named aName in the store file filename. If filename doesn't exist, it's created. The IXFileFinder will search for files in the subtree rooted at the directory named path, which is considered the root path for the IXFileFinder. path can be an absolute or relative pathname If path is NULL, the current working directory will be used. The root path may not be changed after initialization. filename is opened for writing and reading, so that indexes can be created, updated, and cleaned. Returns self.
This is the designated initializer for creating new IXFileFinders with the IXNameAndFileAccess protocol. See also: |
unsigned int crossesDeviceChanges:1;