[h5py] 231/455: Update docs for standalone LZF filter

[Ghislain Vaillant]

This is an automated email from the git hooks/post-receive script.

ghisvail-guest pushed a commit to annotated tag 1.3.0
in repository h5py.

commit cecdba98f2c592f743103d2039097e528d6d2673
Author: andrewcollette <andrew.collette at gmail.com>
Date:   Mon Feb 16 00:44:41 2009 +0000

    Update docs for standalone LZF filter
---
 lzf/README.txt | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 lzf/example.c  | 22 ++++---------------
 2 files changed, 72 insertions(+), 18 deletions(-)

diff --git a/lzf/README.txt b/lzf/README.txt
new file mode 100644
index 0000000..1da33bd
--- /dev/null
+++ b/lzf/README.txt
@@ -0,0 +1,68 @@
+===============================
+LZF filter for HDF5, revision 1
+===============================
+
+The LZF filter provides high-speed compression with acceptable compression
+performance, resulting in much faster performance than DEFLATE, at the
+cost of a slightly worse compression ratio. It's appropriate for large
+datasets of low to moderate complexity, for which some compression is
+much better than none, but for which the speed of DEFLATE is unacceptable.
+
+Both HDF5 versions 1.6 and 1.8 are supported.
+
+
+Using the filter from HDF5
+--------------------------
+
+There is exactly one new public function declared in lzf_filter.h, with
+the following signature:
+
+    int register_lzf(void)
+
+Calling this will register the filter with the HDF5 library.  A non-negative
+return value indicates success.  If the registration fails, an error is pushed
+onto the current error stack and a negative value is returned.
+
+It's strongly recommended to use the SHUFFLE filter with LZF, as it's
+cheap, supported by all current versions of HDF5, and can significantly
+improve the compression ratio.  An example C program ("example.c") is included
+which demonstrates the proper use of the filter.
+
+
+Compiling
+---------
+
+The filter consists of a single .c file and header, along with an embedded
+version of the LZF compression library.  Since the filter is stateless, it's
+recommended to statically link the entire thing into your program; for
+example:
+
+    $ gcc -O2 -lhdf5 lzf/*.c lzf_filter.c myprog.c -o myprog
+
+It can also be built as a shared library, although you will have to install
+the resulting library somewhere the runtime linker can find it:
+
+    $ gcc -02 -lhdf5 -fPIC -shared lzf/*.c lzf_filter.c -o liblzf_filter.so
+
+This filter has not been tested with C++ code.  As in these examples, using
+option -O1 or higher is strongly recommended for increased performance.
+
+
+Contact
+-------
+
+This filter is maintained as part of the HDF5 for Python (h5py) project.  The
+goal of h5py is to provide access to the majority of the HDF5 C API and feature
+set from Python.
+
+* Downloads and bug tracker:        http://h5py.googlecode.com
+
+* Main web site and documentation:  http://h5py.alfven.org
+
+* Contact email:  h5py at alfven dot org
+
+
+
+
+
+
diff --git a/lzf/example.c b/lzf/example.c
index 9dda5a2..23dd776 100644
--- a/lzf/example.c
+++ b/lzf/example.c
@@ -5,21 +5,6 @@
 
     Example program demonstrating use of the LZF filter from C code.
 
-    The LZF filter provides high-speed compression with acceptable compression
-    performance, resulting in much faster performance than DEFLATE, at the
-    cost of a slightly worse compression ratio. It's appropriate for large
-    datasets of low to moderate complexity, for which some compression is
-    much better than none, but for which the speed of DEFLATE is unacceptable.
-
-    It's recommended to use the SHUFFLE filter with LZF, as it's virtually
-    free, supported by all current versions of HDF5, and can significantly
-    improve the compression ratio.
-
-    The filter is completely stateless, and so is safe to statically
-    link into the final program if desired. Using gcc with option -O1
-    or higher is recommended.  The filter can be built with either HDF5
-    1.6 or 1.8, regardless of the HDF5 API compatibility macro settings.
-
     To compile this program:
 
     h5cc -DH5_USE_16_API lzf/*.c lzf_filter.c example.c -o example
@@ -27,16 +12,17 @@
     To run:
 
     $ ./example
+    Success!
     $ h5ls -v test_lzf.hdf5 
     Opened "test_lzf.hdf5" with sec2 driver.
     dset                     Dataset {100/100, 100/100, 100/100}
         Location:  0:1:0:976
         Links:     1
-        Modified:  2009-01-28 21:51:20 PST
+        Modified:  2009-02-15 16:35:11 PST
         Chunks:    {1, 100, 100} 40000 bytes
-        Storage:   4000000 logical bytes, 529745 allocated bytes, 755.08% utilization
+        Storage:   4000000 logical bytes, 174288 allocated bytes, 2295.05% utilization
         Filter-0:  shuffle-2 OPT {4}
-        Filter-1:  lzf-32000 OPT {1, 261, 0}
+        Filter-1:  lzf-32000 OPT {1, 261, 40000}
         Type:      native float
 */
 

-- 
Alioth's /usr/local/bin/git-commit-notice on /srv/git.debian.org/git/debian-science/packages/h5py.git