Changes between Version 1 and Version 2 of ServerDirs

Timestamp:

Mar 26, 2014, 2:59:03 PM (11 years ago)

Author:

davea

Comment:

--

ServerDirs

@@ -34 +34 @@
 The upload and download directories may contain large numbers (millions) of files. For efficiency they are normally organized as a hierarchy of subdirectories. 
 
-== Hierarchical upload/download directories ==
+== Upload and download directory hierarchies ==
 
-The data server for a large project may store 100Ks or millions of files at any given point. If these files are stored in 'flat' directories (project/download and project/upload) the data server may spend a lot of CPU time searching directories. To avoid this, BOINC uses hierarchical upload/download directories. Each directory has a set of 1024 subdirectories, named 0 to 3ff. Files are hashed (based on their filename) into these directories.
+The data server for a large project may store 100Ks or millions of files at a given point.
+If these files are stored in flat directories
+the data server may spend a lot of CPU time searching these directories.
+To avoid this, BOINC uses hierarchical upload and download directories.
+Each directory has a set of 1024 subdirectories, named 0 to 3ff.
+Files are hashed (based on their filename) into these directories.
 
-The hierarchy is used for input and output files only. Executables and other application version files are in the top level of the download directory.
+The hierarchies are used for input and output files only.
+Executables and other application files are in the top level of the download directory.
 
-This affects your project-specific code in a couple of places. First, your work generator must put input files in the right directory before calling [WorkGeneration create_work()]. To do this, it can use the function
+Normally you don't need to know about these hierarchies.
+[JobStage stage_file] automatically puts input files in the right place.
+If for some reason you want to know what directory an input file is in,
+run the command
+{{{
+bin/dir_hier_path filename
+}}}
 
-{{{
-int dir_hier_path(
-    const char* filename, const char* root, int fanout, char* result,
-    bool make_directory_if_needed=false
-);
-}}}
-This takes a name of the input file and the absolute path of the root of the download hierarchy (typically the download_dir element from config.xml) and returns the absolute path of the file in the hierarchy. Generally make_directory_if_needed should be set to true: this creates a fanout directory if needed to accomodate a particular file.
-
-Secondly, your validator and assimilator should call
+For output files, your validator and assimilator should call
 {{{
 int get_output_file_path(RESULT const& result, string& path);
@@ -59 +63 @@
 }}}
 to get the paths of output files in the hierarchy.
-
-A couple of utility programs are available (run this in the project root directory):
-{{{
-dir_hier_move src_dir dst_dir fanout
-dir_hier_path filename
-}}}
-dir_hier_move moves all files from src_dir (flat) into dst_dir (hierarchical with the given fanout). dir_hier_path, given a filename, prints the full pathname of that file in the hierarchy.