-Some quick notes on the file/repository architecture.\r
-\r
-Functionality is, as always, driven by data model. \r
-\r
-* The repository object stores configuration information about a file storage \r
- method.\r
-\r
-* The file object is a process-local cache of information about a particular\r
- file.\r
-\r
-Thus the file object is the primary public entry point for obtaining information\r
-about files, since access via the file object can be cached, whereas access via\r
-the repository should not be cached.\r
-\r
-Functions which can act on any file specified in their parameters typically find\r
-their place either in the repository object, where reference to\r
-repository-specific configuration is needed, or in static members of File or\r
-FileRepo, where no such configuration is needed.\r
-\r
-File objects are generated by a factory function from the repository. The\r
-repository thus has full control over the behaviour of its subsidiary file\r
-class, since it can subclass the file class and override functionality at its\r
-whim. Thus there is no need for the File subclass to query its parent repository\r
-for information about repository-class-dependent behaviour -- the file subclass\r
-is generally fully aware of the static preferences of its repository. Limited\r
-exceptions can be made to this rule to permit sharing of functions, or perhaps\r
-even entire classes, between repositories.\r
-\r
-These rules alone still do lead to some ambiguity -- it may not be clear whether\r
-to implement some functionality in a repository function with a filename\r
-parameter, or in the file object itself. \r
-\r
-So we introduce the following rule: the file subclass is smarter than the \r
-repository subclass. The repository should in general provide a minimal API\r
-needed to access the storage backend efficiently. \r
-\r
-In particular, note that I have not implemented any database access in \r
-LocalRepo.php. LocalRepo provides only file access, and LocalFile provides \r
-database access and higher-level functions such as cache management.\r
-\r
-Tim Starling, June 2007\r
+Some quick notes on the file/repository architecture.
+
+Functionality is, as always, driven by data model.
+
+* The repository object stores configuration information about a file storage
+ method.
+
+* The file object is a process-local cache of information about a particular
+ file.
+
+Thus the file object is the primary public entry point for obtaining information
+about files, since access via the file object can be cached, whereas access via
+the repository should not be cached.
+
+Functions which can act on any file specified in their parameters typically find
+their place either in the repository object, where reference to
+repository-specific configuration is needed, or in static members of File or
+FileRepo, where no such configuration is needed.
+
+File objects are generated by a factory function from the repository. The
+repository thus has full control over the behavior of its subsidiary file
+class, since it can subclass the file class and override functionality at its
+whim. Thus there is no need for the File subclass to query its parent repository
+for information about repository-class-dependent behavior -- the file subclass
+is generally fully aware of the static preferences of its repository. Limited
+exceptions can be made to this rule to permit sharing of functions, or perhaps
+even entire classes, between repositories.
+
+These rules alone still do lead to some ambiguity -- it may not be clear whether
+to implement some functionality in a repository function with a filename
+parameter, or in the file object itself.
+
+So we introduce the following rule: the file subclass is smarter than the
+repository subclass. The repository should in general provide a minimal API
+needed to access the storage backend efficiently.
+
+In particular, note that I have not implemented any database access in
+LocalRepo.php. LocalRepo provides only file access, and LocalFile provides
+database access and higher-level functions such as cache management.
+
+Tim Starling, June 2007
dépôts / lhc / web / wiklou.git / blobdiff