1 /*
2  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 
12 /* This code is in the public domain.
13 ** Version: 1.1  Author: Walt Karas
14 */
15 
16 #include "hmm_intrnl.h"
17 
U(largest_available)18 U(size_aau) U(largest_available)(U(descriptor) *desc) {
19   U(size_bau) largest;
20 
21   if (!(desc->avl_tree_root))
22     largest = 0;
23   else {
24 #ifdef HMM_AUDIT_FAIL
25     /* Audit root block in AVL tree. */
26     AUDIT_BLOCK(PTR_REC_TO_HEAD(desc->avl_tree_root))
27 #endif
28 
29     largest =
30       BLOCK_BAUS(
31         PTR_REC_TO_HEAD(
32           U(avl_search)(
33             (U(avl_avl) *) & (desc->avl_tree_root),
34             (U(size_bau)) ~(U(size_bau)) 0, AVL_LESS)));
35   }
36 
37   if (desc->last_freed) {
38     /* Size of last freed block. */
39     register U(size_bau) lf_size;
40 
41 #ifdef HMM_AUDIT_FAIL
42     AUDIT_BLOCK(desc->last_freed)
43 #endif
44 
45     lf_size = BLOCK_BAUS(desc->last_freed);
46 
47     if (lf_size > largest)
48       largest = lf_size;
49   }
50 
51   /* Convert largest size to AAUs and subract head size leaving payload
52   ** size.
53   */
54   return(largest ?
55          ((largest * ((U(size_aau)) HMM_BLOCK_ALIGN_UNIT)) - HEAD_AAUS) :
56          0);
57 }
58