/src/libfshfs/libfshfs/libfshfs_huffman_tree.c

Source
/*
 * Huffman tree functions
 *
 * Copyright (C) 2009-2026, Joachim Metz <joachim.metz@gmail.com>
 *
 * Refer to AUTHORS for acknowledgements.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#include <common.h>
#include <memory.h>
#include <types.h>

#include "libfshfs_bit_stream.h"
#include "libfshfs_huffman_tree.h"
#include "libfshfs_libcerror.h"
#include "libfshfs_libcnotify.h"

/* Creates a Huffman tree
 * Make sure the value huffman_tree is referencing, is set to NULL
 * Returns 1 if successful or -1 on error
 */
int libfshfs_huffman_tree_initialize(
     libfshfs_huffman_tree_t **huffman_tree,
     int number_of_symbols,
     uint8_t maximum_code_size,
     libcerror_error_t **error )
{
  static char *function = "libfshfs_huffman_tree_initialize";
  size_t array_size     = 0;

  if( huffman_tree == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid Huffman tree.",
     function );

    return( -1 );
  }
  if( *huffman_tree != NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_VALUE_ALREADY_SET,
     "%s: invalid Huffman tree value already set.",
     function );

    return( -1 );
  }
  if( ( number_of_symbols < 0 )
   || ( number_of_symbols > 1024 ) )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_VALUE_OUT_OF_BOUNDS,
     "%s: invalid number of symbols value out of bounds.",
     function );

    return( -1 );
  }
  if( maximum_code_size > 32 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_VALUE_OUT_OF_BOUNDS,
     "%s: invalid maximum code size value out of bounds.",
     function );

    return( -1 );
  }
  *huffman_tree = memory_allocate_structure(
                   libfshfs_huffman_tree_t );

  if( *huffman_tree == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_MEMORY,
     LIBCERROR_MEMORY_ERROR_INSUFFICIENT,
     "%s: unable to create Huffman tree.",
     function );

    goto on_error;
  }
  if( memory_set(
       *huffman_tree,
       0,
       sizeof( libfshfs_huffman_tree_t ) ) == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_MEMORY,
     LIBCERROR_MEMORY_ERROR_SET_FAILED,
     "%s: unable to clear Huffman tree.",
     function );

    memory_free(
     *huffman_tree );

    *huffman_tree = NULL;

    return( -1 );
  }
  array_size = sizeof( uint16_t ) * number_of_symbols;

  ( *huffman_tree )->symbols = (uint16_t *) memory_allocate(
                                             array_size );

  if( ( *huffman_tree )->symbols == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_MEMORY,
     LIBCERROR_MEMORY_ERROR_INSUFFICIENT,
     "%s: unable to create symbols.",
     function );

    goto on_error;
  }
  if( memory_set(
       ( *huffman_tree )->symbols,
       0,
       array_size ) == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_MEMORY,
     LIBCERROR_MEMORY_ERROR_SET_FAILED,
     "%s: unable to clear symbols.",
     function );

    goto on_error;
  }
  array_size = sizeof( int ) * ( maximum_code_size + 1 );

  ( *huffman_tree )->code_size_counts = (int *) memory_allocate(
                                                 array_size );

  if( ( *huffman_tree )->code_size_counts == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_MEMORY,
     LIBCERROR_MEMORY_ERROR_INSUFFICIENT,
     "%s: unable to create code size counts.",
     function );

    goto on_error;
  }
  if( memory_set(
       ( *huffman_tree )->code_size_counts,
       0,
       array_size ) == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_MEMORY,
     LIBCERROR_MEMORY_ERROR_SET_FAILED,
     "%s: unable to clear code size counts.",
     function );

    goto on_error;
  }
  ( *huffman_tree )->maximum_code_size = maximum_code_size;

  return( 1 );

on_error:
  if( *huffman_tree != NULL )
  {
    if( ( *huffman_tree )->code_size_counts != NULL )
    {
      memory_free(
       ( *huffman_tree )->code_size_counts );
    }
    if( ( *huffman_tree )->symbols != NULL )
    {
      memory_free(
       ( *huffman_tree )->symbols );
    }
    memory_free(
     *huffman_tree );

    *huffman_tree = NULL;
  }
  return( -1 );
}

/* Frees a Huffman tree
 * Returns 1 if successful or -1 on error
 */
int libfshfs_huffman_tree_free(
     libfshfs_huffman_tree_t **huffman_tree,
     libcerror_error_t **error )
{
  static char *function = "libfshfs_huffman_tree_free";

  if( huffman_tree == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid Huffman tree.",
     function );

    return( -1 );
  }
  if( *huffman_tree != NULL )
  {
    if( ( *huffman_tree )->code_size_counts != NULL )
    {
      memory_free(
       ( *huffman_tree )->code_size_counts );
    }
    if( ( *huffman_tree )->symbols != NULL )
    {
      memory_free(
       ( *huffman_tree )->symbols );
    }
    memory_free(
     *huffman_tree );

    *huffman_tree = NULL;
  }
  return( 1 );
}

/* Builds the Huffman tree
 * Returns 1 on success, 0 if the tree is empty or -1 on error
 */
int libfshfs_huffman_tree_build(
     libfshfs_huffman_tree_t *huffman_tree,
     const uint8_t *code_sizes_array,
     int number_of_code_sizes,
     libcerror_error_t **error )
{
  int *symbol_offsets   = NULL;
  static char *function = "libfshfs_huffman_tree_build";
  size_t array_size     = 0;
  uint16_t symbol       = 0;
  uint8_t bit_index     = 0;
  uint8_t code_size     = 0;
  int code_offset       = 0;
  int left_value        = 0;

  if( huffman_tree == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid Huffman tree.",
     function );

    return( -1 );
  }
  if( huffman_tree->maximum_code_size == 0 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
     "%s: invalid Huffman tree - maximum code size value out of bounds.",
     function );

    return( -1 );
  }
  if( code_sizes_array == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid code sizes array.",
     function );

    return( -1 );
  }
  if( ( number_of_code_sizes < 0 )
   || ( number_of_code_sizes > (int) INT16_MAX ) )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_VALUE_OUT_OF_BOUNDS,
     "%s: invalid number of code sizes value out of bounds.",
     function );

    return( -1 );
  }
  /* Determine the code size frequencies
   */
  array_size = sizeof( int ) * ( huffman_tree->maximum_code_size + 1 );

  if( memory_set(
       huffman_tree->code_size_counts,
       0,
       array_size ) == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_MEMORY,
     LIBCERROR_MEMORY_ERROR_SET_FAILED,
     "%s: unable to clear code size counts.",
     function );

    goto on_error;
  }
  for( symbol = 0;
       symbol < (uint16_t) number_of_code_sizes;
       symbol++ )
  {
    code_size = code_sizes_array[ symbol ];

    if( code_size > huffman_tree->maximum_code_size )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_RUNTIME,
       LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
       "%s: invalid symbol: %d code size: %" PRIu8 " value out of bounds.",
       function,
       symbol,
       code_size );

      goto on_error;
    }
    huffman_tree->code_size_counts[ code_size ] += 1;
  }
  /* The tree has no codes
   */
  if( huffman_tree->code_size_counts[ 0 ] == number_of_code_sizes )
  {
    return( 0 );
  }
  /* Check if the set of code sizes is incomplete or over-subscribed
   */
  left_value = 1;

  for( bit_index = 1;
       bit_index <= huffman_tree->maximum_code_size;
       bit_index++ )
  {
    left_value <<= 1;
    left_value  -= huffman_tree->code_size_counts[ bit_index ];

    if( left_value < 0 )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_RUNTIME,
       LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
       "%s: code sizes are over-subscribed.",
       function );

      goto on_error;
    }
  }
/* TODO
  if( left_value > 0 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
     "%s: code sizes are incomplete.",
     function );

    goto on_error;
  }
*/
  symbol_offsets = (int *) memory_allocate(
                            array_size );

  if( symbol_offsets == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_MEMORY,
     LIBCERROR_MEMORY_ERROR_INSUFFICIENT,
     "%s: unable to create symbol offsets.",
     function );

    goto on_error;
  }
  /* Calculate the offsets to sort the symbols per code size
   */
  symbol_offsets[ 0 ] = 0;
  symbol_offsets[ 1 ] = 0;

  for( bit_index = 1;
       bit_index < huffman_tree->maximum_code_size;
       bit_index++ )
  {
    symbol_offsets[ bit_index + 1 ] = symbol_offsets[ bit_index ] + huffman_tree->code_size_counts[ bit_index ];
  }
  /* Fill the symbols sorted by code size
   */
  for( symbol = 0;
       symbol < (uint16_t) number_of_code_sizes;
       symbol++ )
  {
    code_size = code_sizes_array[ symbol ];

    if( code_size == 0 )
    {
      continue;
    }
    code_offset = symbol_offsets[ code_size ];

    if( ( code_offset < 0 )
     || ( code_offset > number_of_code_sizes ) )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_RUNTIME,
       LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
       "%s: invalid symbol: %" PRIu16 " code offset: %d value out of bounds.",
       function,
       symbol,
       code_offset );

      goto on_error;
    }
    symbol_offsets[ code_size ] += 1;

    huffman_tree->symbols[ code_offset ] = symbol;
  }
  memory_free(
   symbol_offsets );

  return( 1 );

on_error:
  if( symbol_offsets != NULL )
  {
    memory_free(
     symbol_offsets );
  }
  return( -1 );
}

/* Retrieves a symbol based on the Huffman code read from the bit-stream
 * Returns 1 on success or -1 on error
 */
int libfshfs_huffman_tree_get_symbol_from_bit_stream(
     libfshfs_huffman_tree_t *huffman_tree,
     libfshfs_bit_stream_t *bit_stream,
     uint16_t *symbol,
     libcerror_error_t **error )
{
  static char *function  = "libfshfs_huffman_tree_get_symbol_from_bit_stream";
  uint32_t value_32bit   = 0;
  uint16_t safe_symbol   = 0;
  uint8_t bit_index      = 0;
  int code_size_count    = 0;
  int first_huffman_code = 0;
  int first_index        = 0;
  int huffman_code       = 0;
  int result             = 0;

  if( huffman_tree == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid Huffman tree.",
     function );

    return( -1 );
  }
  if( bit_stream == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid bit stream.",
     function );

    return( -1 );
  }
  if( symbol == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid symbol.",
     function );

    return( -1 );
  }
/* TODO get maximum_code_size of bits into local bit buffer */

  for( bit_index = 1;
       bit_index <= huffman_tree->maximum_code_size;
       bit_index++ )
  {
    if( libfshfs_bit_stream_get_value(
         bit_stream,
         1,
         &value_32bit,
         error ) != 1 )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_RUNTIME,
       LIBCERROR_RUNTIME_ERROR_GET_FAILED,
       "%s: unable to retrieve value from bit stream.",
       function );

      return( -1 );
    }
    huffman_code <<= 1;
    huffman_code  |= (int) value_32bit;

    code_size_count = huffman_tree->code_size_counts[ bit_index ];

    if( ( huffman_code - code_size_count ) < first_huffman_code )
    {
      safe_symbol = huffman_tree->symbols[ first_index + ( huffman_code - first_huffman_code ) ];

      result = 1;

      break;
    }
    first_huffman_code  += code_size_count;
    first_huffman_code <<= 1;
    first_index         += code_size_count;
  }
  if( result != 1 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
     "%s: invalid Huffman code: 0x%08" PRIx32 ".",
     function,
     huffman_code );

    return( -1 );
  }
  *symbol = safe_symbol;

  return( 1 );
}


Coverage Report

Created: 2026-07-10 07:32

Line	Count	Source
1		/*
2		* Huffman tree functions
3		*
4		* Copyright (C) 2009-2026, Joachim Metz <joachim.metz@gmail.com>
5		*
6		* Refer to AUTHORS for acknowledgements.
7		*
8		* This program is free software: you can redistribute it and/or modify
9		* it under the terms of the GNU Lesser General Public License as published by
10		* the Free Software Foundation, either version 3 of the License, or
11		* (at your option) any later version.
12		*
13		* This program is distributed in the hope that it will be useful,
14		* but WITHOUT ANY WARRANTY; without even the implied warranty of
15		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16		* GNU General Public License for more details.
17		*
18		* You should have received a copy of the GNU Lesser General Public License
19		* along with this program. If not, see <https://www.gnu.org/licenses/>.
20		*/
21
22		#include <common.h>
23		#include <memory.h>
24		#include <types.h>
25
26		#include "libfshfs_bit_stream.h"
27		#include "libfshfs_huffman_tree.h"
28		#include "libfshfs_libcerror.h"
29		#include "libfshfs_libcnotify.h"
30
31		/* Creates a Huffman tree
32		* Make sure the value huffman_tree is referencing, is set to NULL
33		* Returns 1 if successful or -1 on error
34		*/
35		int libfshfs_huffman_tree_initialize(
36		libfshfs_huffman_tree_t **huffman_tree,
37		int number_of_symbols,
38		uint8_t maximum_code_size,
39		libcerror_error_t **error )
40	0	{
41	0	static char *function = "libfshfs_huffman_tree_initialize";
42	0	size_t array_size = 0;
43
44	0	if( huffman_tree == NULL )
45	0	{
46	0	libcerror_error_set(
47	0	error,
48	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
49	0	LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
50	0	"%s: invalid Huffman tree.",
51	0	function );
52
53	0	return( -1 );
54	0	}
55	0	if( *huffman_tree != NULL )
56	0	{
57	0	libcerror_error_set(
58	0	error,
59	0	LIBCERROR_ERROR_DOMAIN_RUNTIME,
60	0	LIBCERROR_RUNTIME_ERROR_VALUE_ALREADY_SET,
61	0	"%s: invalid Huffman tree value already set.",
62	0	function );
63
64	0	return( -1 );
65	0	}
66	0	if( ( number_of_symbols < 0 )
67	0	\|\| ( number_of_symbols > 1024 ) )
68	0	{
69	0	libcerror_error_set(
70	0	error,
71	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
72	0	LIBCERROR_ARGUMENT_ERROR_VALUE_OUT_OF_BOUNDS,
73	0	"%s: invalid number of symbols value out of bounds.",
74	0	function );
75
76	0	return( -1 );
77	0	}
78	0	if( maximum_code_size > 32 )
79	0	{
80	0	libcerror_error_set(
81	0	error,
82	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
83	0	LIBCERROR_ARGUMENT_ERROR_VALUE_OUT_OF_BOUNDS,
84	0	"%s: invalid maximum code size value out of bounds.",
85	0	function );
86
87	0	return( -1 );
88	0	}
89	0	*huffman_tree = memory_allocate_structure(
90	0	libfshfs_huffman_tree_t );
91
92	0	if( *huffman_tree == NULL )
93	0	{
94	0	libcerror_error_set(
95	0	error,
96	0	LIBCERROR_ERROR_DOMAIN_MEMORY,
97	0	LIBCERROR_MEMORY_ERROR_INSUFFICIENT,
98	0	"%s: unable to create Huffman tree.",
99	0	function );
100
101	0	goto on_error;
102	0	}
103	0	if( memory_set(
104	0	*huffman_tree,
105	0	0,
106	0	sizeof( libfshfs_huffman_tree_t ) ) == NULL )
107	0	{
108	0	libcerror_error_set(
109	0	error,
110	0	LIBCERROR_ERROR_DOMAIN_MEMORY,
111	0	LIBCERROR_MEMORY_ERROR_SET_FAILED,
112	0	"%s: unable to clear Huffman tree.",
113	0	function );
114
115	0	memory_free(
116	0	*huffman_tree );
117
118	0	*huffman_tree = NULL;
119
120	0	return( -1 );
121	0	}
122	0	array_size = sizeof( uint16_t ) * number_of_symbols;
123
124	0	( huffman_tree )->symbols = (uint16_t ) memory_allocate(
125	0	array_size );
126
127	0	if( ( *huffman_tree )->symbols == NULL )
128	0	{
129	0	libcerror_error_set(
130	0	error,
131	0	LIBCERROR_ERROR_DOMAIN_MEMORY,
132	0	LIBCERROR_MEMORY_ERROR_INSUFFICIENT,
133	0	"%s: unable to create symbols.",
134	0	function );
135
136	0	goto on_error;
137	0	}
138	0	if( memory_set(
139	0	( *huffman_tree )->symbols,
140	0	0,
141	0	array_size ) == NULL )
142	0	{
143	0	libcerror_error_set(
144	0	error,
145	0	LIBCERROR_ERROR_DOMAIN_MEMORY,
146	0	LIBCERROR_MEMORY_ERROR_SET_FAILED,
147	0	"%s: unable to clear symbols.",
148	0	function );
149
150	0	goto on_error;
151	0	}
152	0	array_size = sizeof( int ) * ( maximum_code_size + 1 );
153
154	0	( huffman_tree )->code_size_counts = (int ) memory_allocate(
155	0	array_size );
156
157	0	if( ( *huffman_tree )->code_size_counts == NULL )
158	0	{
159	0	libcerror_error_set(
160	0	error,
161	0	LIBCERROR_ERROR_DOMAIN_MEMORY,
162	0	LIBCERROR_MEMORY_ERROR_INSUFFICIENT,
163	0	"%s: unable to create code size counts.",
164	0	function );
165
166	0	goto on_error;
167	0	}
168	0	if( memory_set(
169	0	( *huffman_tree )->code_size_counts,
170	0	0,
171	0	array_size ) == NULL )
172	0	{
173	0	libcerror_error_set(
174	0	error,
175	0	LIBCERROR_ERROR_DOMAIN_MEMORY,
176	0	LIBCERROR_MEMORY_ERROR_SET_FAILED,
177	0	"%s: unable to clear code size counts.",
178	0	function );
179
180	0	goto on_error;
181	0	}
182	0	( *huffman_tree )->maximum_code_size = maximum_code_size;
183
184	0	return( 1 );
185
186	0	on_error:
187	0	if( *huffman_tree != NULL )
188	0	{
189	0	if( ( *huffman_tree )->code_size_counts != NULL )
190	0	{
191	0	memory_free(
192	0	( *huffman_tree )->code_size_counts );
193	0	}
194	0	if( ( *huffman_tree )->symbols != NULL )
195	0	{
196	0	memory_free(
197	0	( *huffman_tree )->symbols );
198	0	}
199	0	memory_free(
200	0	*huffman_tree );
201
202	0	*huffman_tree = NULL;
203	0	}
204	0	return( -1 );
205	0	}
206
207		/* Frees a Huffman tree
208		* Returns 1 if successful or -1 on error
209		*/
210		int libfshfs_huffman_tree_free(
211		libfshfs_huffman_tree_t **huffman_tree,
212		libcerror_error_t **error )
213	0	{
214	0	static char *function = "libfshfs_huffman_tree_free";
215
216	0	if( huffman_tree == NULL )
217	0	{
218	0	libcerror_error_set(
219	0	error,
220	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
221	0	LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
222	0	"%s: invalid Huffman tree.",
223	0	function );
224
225	0	return( -1 );
226	0	}
227	0	if( *huffman_tree != NULL )
228	0	{
229	0	if( ( *huffman_tree )->code_size_counts != NULL )
230	0	{
231	0	memory_free(
232	0	( *huffman_tree )->code_size_counts );
233	0	}
234	0	if( ( *huffman_tree )->symbols != NULL )
235	0	{
236	0	memory_free(
237	0	( *huffman_tree )->symbols );
238	0	}
239	0	memory_free(
240	0	*huffman_tree );
241
242	0	*huffman_tree = NULL;
243	0	}
244	0	return( 1 );
245	0	}
246
247		/* Builds the Huffman tree
248		* Returns 1 on success, 0 if the tree is empty or -1 on error
249		*/
250		int libfshfs_huffman_tree_build(
251		libfshfs_huffman_tree_t *huffman_tree,
252		const uint8_t *code_sizes_array,
253		int number_of_code_sizes,
254		libcerror_error_t **error )
255	0	{
256	0	int *symbol_offsets = NULL;
257	0	static char *function = "libfshfs_huffman_tree_build";
258	0	size_t array_size = 0;
259	0	uint16_t symbol = 0;
260	0	uint8_t bit_index = 0;
261	0	uint8_t code_size = 0;
262	0	int code_offset = 0;
263	0	int left_value = 0;
264
265	0	if( huffman_tree == NULL )
266	0	{
267	0	libcerror_error_set(
268	0	error,
269	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
270	0	LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
271	0	"%s: invalid Huffman tree.",
272	0	function );
273
274	0	return( -1 );
275	0	}
276	0	if( huffman_tree->maximum_code_size == 0 )
277	0	{
278	0	libcerror_error_set(
279	0	error,
280	0	LIBCERROR_ERROR_DOMAIN_RUNTIME,
281	0	LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
282	0	"%s: invalid Huffman tree - maximum code size value out of bounds.",
283	0	function );
284
285	0	return( -1 );
286	0	}
287	0	if( code_sizes_array == NULL )
288	0	{
289	0	libcerror_error_set(
290	0	error,
291	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
292	0	LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
293	0	"%s: invalid code sizes array.",
294	0	function );
295
296	0	return( -1 );
297	0	}
298	0	if( ( number_of_code_sizes < 0 )
299	0	\|\| ( number_of_code_sizes > (int) INT16_MAX ) )
300	0	{
301	0	libcerror_error_set(
302	0	error,
303	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
304	0	LIBCERROR_ARGUMENT_ERROR_VALUE_OUT_OF_BOUNDS,
305	0	"%s: invalid number of code sizes value out of bounds.",
306	0	function );
307
308	0	return( -1 );
309	0	}
310		/* Determine the code size frequencies
311		*/
312	0	array_size = sizeof( int ) * ( huffman_tree->maximum_code_size + 1 );
313
314	0	if( memory_set(
315	0	huffman_tree->code_size_counts,
316	0	0,
317	0	array_size ) == NULL )
318	0	{
319	0	libcerror_error_set(
320	0	error,
321	0	LIBCERROR_ERROR_DOMAIN_MEMORY,
322	0	LIBCERROR_MEMORY_ERROR_SET_FAILED,
323	0	"%s: unable to clear code size counts.",
324	0	function );
325
326	0	goto on_error;
327	0	}
328	0	for( symbol = 0;
329	0	symbol < (uint16_t) number_of_code_sizes;
330	0	symbol++ )
331	0	{
332	0	code_size = code_sizes_array[ symbol ];
333
334	0	if( code_size > huffman_tree->maximum_code_size )
335	0	{
336	0	libcerror_error_set(
337	0	error,
338	0	LIBCERROR_ERROR_DOMAIN_RUNTIME,
339	0	LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
340	0	"%s: invalid symbol: %d code size: %" PRIu8 " value out of bounds.",
341	0	function,
342	0	symbol,
343	0	code_size );
344
345	0	goto on_error;
346	0	}
347	0	huffman_tree->code_size_counts[ code_size ] += 1;
348	0	}
349		/* The tree has no codes
350		*/
351	0	if( huffman_tree->code_size_counts[ 0 ] == number_of_code_sizes )
352	0	{
353	0	return( 0 );
354	0	}
355		/* Check if the set of code sizes is incomplete or over-subscribed
356		*/
357	0	left_value = 1;
358
359	0	for( bit_index = 1;
360	0	bit_index <= huffman_tree->maximum_code_size;
361	0	bit_index++ )
362	0	{
363	0	left_value <<= 1;
364	0	left_value -= huffman_tree->code_size_counts[ bit_index ];
365
366	0	if( left_value < 0 )
367	0	{
368	0	libcerror_error_set(
369	0	error,
370	0	LIBCERROR_ERROR_DOMAIN_RUNTIME,
371	0	LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
372	0	"%s: code sizes are over-subscribed.",
373	0	function );
374
375	0	goto on_error;
376	0	}
377	0	}
378		/* TODO
379		if( left_value > 0 )
380		{
381		libcerror_error_set(
382		error,
383		LIBCERROR_ERROR_DOMAIN_RUNTIME,
384		LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
385		"%s: code sizes are incomplete.",
386		function );
387
388		goto on_error;
389		}
390		*/
391	0	symbol_offsets = (int *) memory_allocate(
392	0	array_size );
393
394	0	if( symbol_offsets == NULL )
395	0	{
396	0	libcerror_error_set(
397	0	error,
398	0	LIBCERROR_ERROR_DOMAIN_MEMORY,
399	0	LIBCERROR_MEMORY_ERROR_INSUFFICIENT,
400	0	"%s: unable to create symbol offsets.",
401	0	function );
402
403	0	goto on_error;
404	0	}
405		/* Calculate the offsets to sort the symbols per code size
406		*/
407	0	symbol_offsets[ 0 ] = 0;
408	0	symbol_offsets[ 1 ] = 0;
409
410	0	for( bit_index = 1;
411	0	bit_index < huffman_tree->maximum_code_size;
412	0	bit_index++ )
413	0	{
414	0	symbol_offsets[ bit_index + 1 ] = symbol_offsets[ bit_index ] + huffman_tree->code_size_counts[ bit_index ];
415	0	}
416		/* Fill the symbols sorted by code size
417		*/
418	0	for( symbol = 0;
419	0	symbol < (uint16_t) number_of_code_sizes;
420	0	symbol++ )
421	0	{
422	0	code_size = code_sizes_array[ symbol ];
423
424	0	if( code_size == 0 )
425	0	{
426	0	continue;
427	0	}
428	0	code_offset = symbol_offsets[ code_size ];
429
430	0	if( ( code_offset < 0 )
431	0	\|\| ( code_offset > number_of_code_sizes ) )
432	0	{
433	0	libcerror_error_set(
434	0	error,
435	0	LIBCERROR_ERROR_DOMAIN_RUNTIME,
436	0	LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
437	0	"%s: invalid symbol: %" PRIu16 " code offset: %d value out of bounds.",
438	0	function,
439	0	symbol,
440	0	code_offset );
441
442	0	goto on_error;
443	0	}
444	0	symbol_offsets[ code_size ] += 1;
445
446	0	huffman_tree->symbols[ code_offset ] = symbol;
447	0	}
448	0	memory_free(
449	0	symbol_offsets );
450
451	0	return( 1 );
452
453	0	on_error:
454	0	if( symbol_offsets != NULL )
455	0	{
456	0	memory_free(
457	0	symbol_offsets );
458	0	}
459	0	return( -1 );
460	0	}
461
462		/* Retrieves a symbol based on the Huffman code read from the bit-stream
463		* Returns 1 on success or -1 on error
464		*/
465		int libfshfs_huffman_tree_get_symbol_from_bit_stream(
466		libfshfs_huffman_tree_t *huffman_tree,
467		libfshfs_bit_stream_t *bit_stream,
468		uint16_t *symbol,
469		libcerror_error_t **error )
470	0	{
471	0	static char *function = "libfshfs_huffman_tree_get_symbol_from_bit_stream";
472	0	uint32_t value_32bit = 0;
473	0	uint16_t safe_symbol = 0;
474	0	uint8_t bit_index = 0;
475	0	int code_size_count = 0;
476	0	int first_huffman_code = 0;
477	0	int first_index = 0;
478	0	int huffman_code = 0;
479	0	int result = 0;
480
481	0	if( huffman_tree == NULL )
482	0	{
483	0	libcerror_error_set(
484	0	error,
485	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
486	0	LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
487	0	"%s: invalid Huffman tree.",
488	0	function );
489
490	0	return( -1 );
491	0	}
492	0	if( bit_stream == NULL )
493	0	{
494	0	libcerror_error_set(
495	0	error,
496	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
497	0	LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
498	0	"%s: invalid bit stream.",
499	0	function );
500
501	0	return( -1 );
502	0	}
503	0	if( symbol == NULL )
504	0	{
505	0	libcerror_error_set(
506	0	error,
507	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
508	0	LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
509	0	"%s: invalid symbol.",
510	0	function );
511
512	0	return( -1 );
513	0	}
514		/* TODO get maximum_code_size of bits into local bit buffer */
515
516	0	for( bit_index = 1;
517	0	bit_index <= huffman_tree->maximum_code_size;
518	0	bit_index++ )
519	0	{
520	0	if( libfshfs_bit_stream_get_value(
521	0	bit_stream,
522	0	1,
523	0	&value_32bit,
524	0	error ) != 1 )
525	0	{
526	0	libcerror_error_set(
527	0	error,
528	0	LIBCERROR_ERROR_DOMAIN_RUNTIME,
529	0	LIBCERROR_RUNTIME_ERROR_GET_FAILED,
530	0	"%s: unable to retrieve value from bit stream.",
531	0	function );
532
533	0	return( -1 );
534	0	}
535	0	huffman_code <<= 1;
536	0	huffman_code \|= (int) value_32bit;
537
538	0	code_size_count = huffman_tree->code_size_counts[ bit_index ];
539
540	0	if( ( huffman_code - code_size_count ) < first_huffman_code )
541	0	{
542	0	safe_symbol = huffman_tree->symbols[ first_index + ( huffman_code - first_huffman_code ) ];
543
544	0	result = 1;
545
546	0	break;
547	0	}
548	0	first_huffman_code += code_size_count;
549	0	first_huffman_code <<= 1;
550	0	first_index += code_size_count;
551	0	}
552	0	if( result != 1 )
553	0	{
554	0	libcerror_error_set(
555	0	error,
556	0	LIBCERROR_ERROR_DOMAIN_RUNTIME,
557	0	LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
558	0	"%s: invalid Huffman code: 0x%08" PRIx32 ".",
559	0	function,
560	0	huffman_code );
561
562	0	return( -1 );
563	0	}
564	0	*symbol = safe_symbol;
565
566	0	return( 1 );
567	0	}
568