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      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 
     18 U(size_aau) U(largest_available)(U(descriptor) *desc)
     19 {
     20     U(size_bau) largest;
     21 
     22     if (!(desc->avl_tree_root))
     23         largest = 0;
     24     else
     25     {
     26 #ifdef HMM_AUDIT_FAIL
     27         /* Audit root block in AVL tree. */
     28         AUDIT_BLOCK(PTR_REC_TO_HEAD(desc->avl_tree_root))
     29 #endif
     30 
     31         largest =
     32             BLOCK_BAUS(
     33                 PTR_REC_TO_HEAD(
     34                     U(avl_search)(
     35                         (U(avl_avl) *) & (desc->avl_tree_root),
     36                         (U(size_bau)) ~(U(size_bau)) 0, AVL_LESS)));
     37     }
     38 
     39     if (desc->last_freed)
     40     {
     41         /* Size of last freed block. */
     42         register U(size_bau) lf_size;
     43 
     44 #ifdef HMM_AUDIT_FAIL
     45         AUDIT_BLOCK(desc->last_freed)
     46 #endif
     47 
     48         lf_size = BLOCK_BAUS(desc->last_freed);
     49 
     50         if (lf_size > largest)
     51             largest = lf_size;
     52     }
     53 
     54     /* Convert largest size to AAUs and subract head size leaving payload
     55     ** size.
     56     */
     57     return(largest ?
     58            ((largest * ((U(size_aau)) HMM_BLOCK_ALIGN_UNIT)) - HEAD_AAUS) :
     59            0);
     60 }
     61