Changeset 146

Timestamp:

06/07/10 08:04:42 (3 years ago)

Author:

faltet

Message:

Added 3 new functions for querying different metadata on compressed
buffers:

void blosc_cbuffer_sizes(const void *cbuffer, size_t *nbytes,

size_t *cbytes);

void blosc_cbuffer_metainfo(const void *cbuffer, size_t *typesize,

int *shuffle);

void blosc_cbuffer_versions(const void *cbuffer, int *version,

int *versionlz);

A test suite for testing the new API has been added too.

Location:

trunk

Files:

• RELEASE_NOTES.txt (modified) (1 diff)
• src/blosc.c (modified) (1 diff)
• src/blosc.h (modified) (1 diff)
• tests (added)
• tests/Makefile (added)
• tests/test_api.c (added)

trunk/RELEASE_NOTES.txt

@@ -10 +10 @@
 ===========================
 
-- None yet.
+- Added 3 new functions for querying different metadata on compressed
+  buffers.  A test suite for testing the new API has been added too.
 
 

trunk/src/blosc.c

@@ -682 +682 @@
   assert(ntbytes <= (int32_t)dest_size);
   return ntbytes;
+}
+
+
+/* Return information about a compressed buffer, namely the number of
+   uncompressed bytes (`nbytes`) and compressed (`cbytes`).  This
+   function should always succeed. */
+void blosc_cbuffer_sizes(const void *cbuffer, size_t *nbytes,
+                         size_t *cbytes)
+{
+  uint8_t *_src = (uint8_t *)(cbuffer);    /* current pos for source buffer */
+  uint8_t version, versionlz;              /* versions for compressed header */
+
+  /* Read the version info (could be useful in the future) */
+  version = _src[0];                         /* blosc format version */
+  versionlz = _src[1];                       /* blosclz format version */
+
+  /* Read the interesting values */
+  _src += 4;
+  *nbytes = (size_t)sw32(((uint32_t *)_src)[0]);   /* buffer size */
+  *cbytes = (size_t)sw32(((uint32_t *)_src)[2]);   /* compressed buffer size */
+}
+
+
+/* Return information about a compressed buffer, namely the type size
+   (`typesize`), and whether the shuffle filter has been applied or
+   not (`shuffle`).  This function should always succeed. */
+void blosc_cbuffer_metainfo(const void *cbuffer, size_t *typesize,
+                            int *shuffle)
+{
+  uint8_t *_src = (uint8_t *)(cbuffer);  /* current pos for source buffer */
+  uint8_t version, versionlz;            /* versions for compressed header */
+  uint8_t flags;                         /* flags for header */
+
+  /* Read the version info (could be useful in the future) */
+  version = _src[0];                     /* blosc format version */
+  versionlz = _src[1];                   /* blosclz format version */
+
+  /* Read the interesting values */
+  flags = _src[2];                       /* flags */
+  *typesize = (size_t)_src[3];           /* typesize */
+
+  /* Shuffle info */
+  if ((flags & 0x1) == 1) {
+    /* Input is shuffled.  Unshuffle it. */
+    *shuffle = 1;
+  }
+  else {
+    *shuffle = 0;
+  }
+}
+
+
+/* Return information about a compressed buffer, namely the internal
+   Blosc format version (`version`) and the format for the internal
+   Lempel-Ziv algorithm (`versionlz`).  This function should always
+   succeed. */
+void blosc_cbuffer_versions(const void *cbuffer, int *version,
+                            int *versionlz)
+{
+  uint8_t *_src = (uint8_t *)(cbuffer);  /* current pos for source buffer */
+
+  /* Read the version info */
+  *version = (int)(_src[0]);             /* blosc format version */
+  *versionlz = (int)(_src[1]);           /* blosclz format version */
 }
 

trunk/src/blosc.h

@@ -109 +109 @@
 
 
+/**
+
+  Return information about a compressed buffer, namely the number of
+  uncompressed bytes (`nbytes`) and compressed (`cbytes`).  This
+  function should always succeed.
+
+*/
+
+void blosc_cbuffer_sizes(const void *cbuffer, size_t *nbytes,
+                         size_t *cbytes);
+
+
+/**
+
+  Return information about a compressed buffer, namely the type size
+  (`typesize`), and whether the shuffle filter has been applied or not
+  (`shuffle`).  This function should always succeed.
+
+*/
+
+void blosc_cbuffer_metainfo(const void *cbuffer, size_t *typesize,
+                            int *shuffle);
+
+
+/**
+
+  Return information about a compressed buffer, namely the internal
+  Blosc format version (`version`) and the format for the internal
+  Lempel-Ziv algorithm (`versionlz`).  This function should always
+  succeed.
+
+*/
+
+void blosc_cbuffer_versions(const void *cbuffer, int *version,
+                            int *versionlz);
+
+
 
 /*********************************************************************