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| author | Frank Baker <fbaker@hdfgroup.org> | 2000-08-25 17:42:24 (GMT) |
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| committer | Frank Baker <fbaker@hdfgroup.org> | 2000-08-25 17:42:24 (GMT) |
| commit | 2e8cd59163cda6b051eae53aac58f54e0a9e9351 (patch) | |
| tree | 5d9058906b7a9a39b0815476d7daea0229c67eb4 /doc/html/TechNotes/HeapMgmt.html | |
| parent | 3ff571ab58fedf8dbb20ac8e1eea251ffb343f9e (diff) | |
| download | hdf5-2e8cd59163cda6b051eae53aac58f54e0a9e9351.zip hdf5-2e8cd59163cda6b051eae53aac58f54e0a9e9351.tar.gz hdf5-2e8cd59163cda6b051eae53aac58f54e0a9e9351.tar.bz2 | |
[svn-r2482] Bringing "HDF5 Technical Notes" into development branch (from R1.2 branch)
Diffstat (limited to 'doc/html/TechNotes/HeapMgmt.html')
| -rw-r--r-- | doc/html/TechNotes/HeapMgmt.html | 84 |
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diff --git a/doc/html/TechNotes/HeapMgmt.html b/doc/html/TechNotes/HeapMgmt.html new file mode 100644 index 0000000..e9e8db4 --- /dev/null +++ b/doc/html/TechNotes/HeapMgmt.html @@ -0,0 +1,84 @@ +<html> +<body> + +<h1>Heap Management in HDF5</h1> + +<pre> + +Heap functions are in the H5H package. + + +off_t +H5H_new (hdf5_file_t *f, size_t size_hint, size_t realloc_hint); + + Creates a new heap in the specified file which can efficiently + store at least SIZE_HINT bytes. The heap can store more than + that, but doing so may cause the heap to become less efficient + (for instance, a heap implemented as a B-tree might become + discontigous). The REALLOC_HINT is the minimum number of bytes + by which the heap will grow when it must be resized. The hints + may be zero in which case reasonable (but probably not + optimal) values will be chosen. + + The return value is the address of the new heap relative to + the beginning of the file boot block. + +off_t +H5H_insert (hdf5_file_t *f, off_t addr, size_t size, const void *buf); + + Copies SIZE bytes of data from BUF into the heap whose address + is ADDR in file F. BUF must be the _entire_ heap object. The + return value is the byte offset of the new data in the heap. + +void * +H5H_read (hdf5_file_t *f, off_t addr, off_t offset, size_t size, void *buf); + + Copies SIZE bytes of data from the heap whose address is ADDR + in file F into BUF and then returns the address of BUF. If + BUF is the null pointer then a new buffer will be malloc'd by + this function and its address is returned. + + Returns buffer address or null. + +const void * +H5H_peek (hdf5_file_t *f, off_t addr, off_t offset) + + A more efficient version of H5H_read that returns a pointer + directly into the cache; the data is not copied from the cache + to a buffer. The pointer is valid until the next call to an + H5AC function directly or indirectly. + + Returns a pointer or null. Do not free the pointer. + +void * +H5H_write (hdf5_file_t *f, off_t addr, off_t offset, size_t size, + const void *buf); + + Modifies (part of) an object in the heap at address ADDR of + file F by copying SIZE bytes from the beginning of BUF to the + file. OFFSET is the address withing the heap where the output + is to occur. + + This function can fail if the combination of OFFSET and SIZE + would write over a boundary between two heap objects. + +herr_t +H5H_remove (hdf5_file_t *f, off_t addr, off_t offset, size_t size); + + Removes an object or part of an object which begins at byte + OFFSET within a heap whose address is ADDR in file F. SIZE + bytes are returned to the free list. Removing the middle of + an object has the side effect that one object is now split + into two objects. + + Returns success or failure. + +=========================================== +Last Modified: 8 July 1998 (technical content) +Last Modified: 28 April 2000 (included in HDF5 Technical Notes) +HDF Help Desk: hdfhelp@ncsa.uiuc.edu + +</pre> + +</body> +</html> |