Methods and apparatus for retrieval of content units in a time-based directory structure

At least one computer readable medium encoded with instructions that, when executed on a computer system, perform a method of accessing information in a hierarchical file system having a plurality of directories arranged in a hierarchical tree, comprising at least one root directory and a plurality of non-root directories that each has a parent directory, wherein at least some of the plurality of directories in the tree correspond to a period of time subsumed by a period of time corresponding to its respective parent directory, the method comprising acts of:

• (A) receiving a request to access a unit of information in the file system, wherein the request includes an identifier for the unit of information, and wherein the identifier does not identify a time related to a time of storage of the unit of information;
• (B) mapping the identifier into a time value using a mapping function that produces a reproducible time value for the identifier;
• and
• (C) selecting a directory from the plurality of directories, wherein the selected directory corresponds to the time value to which the identifier is mapped.

At least one computer that maintains a hierarchical file system having a plurality of directories arranged in a hierarchical tree, comprising at least one root directory and a plurality of non-root directories that each has a parent directory, wherein at least some of the plurality of directories in the tree correspond to a period of time subsumed by a period of time corresponding to its respective parent directory, the at least one computer comprising:

• at least one input;
• and
• at least one controller, coupled to that at least one input, that
• (A) receives, from the at least one input, a request to access a unit of information in the file system, wherein the request includes an identifier for the unit of information, and wherein the identifier does not identify a time related to a time of storage of the unit of information;
• (B) maps the identifier into a time value using a mapping function that produces a reproducible time value for the identifier;
• and
• (C) selects a directory from the plurality of directories, wherein the selected directory corresponds to the time value to which the identifier is mapped.