1 | /*
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2 | * Copyright (c) 2012 Sean Bartell
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3 | * All rights reserved.
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4 | *
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5 | * Redistribution and use in source and binary forms, with or without
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6 | * modification, are permitted provided that the following conditions
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7 | * are met:
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8 | *
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9 | * - Redistributions of source code must retain the above copyright
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10 | * notice, this list of conditions and the following disclaimer.
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11 | * - Redistributions in binary form must reproduce the above copyright
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12 | * notice, this list of conditions and the following disclaimer in the
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13 | * documentation and/or other materials provided with the distribution.
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14 | * - The name of the author may not be used to endorse or promote products
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15 | * derived from this software without specific prior written permission.
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16 | *
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17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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27 | */
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28 |
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29 | /** @addtogroup bithenge
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30 | * @{
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31 | */
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32 | /**
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33 | * @file
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34 | * Raw binary blobs.
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35 | */
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36 |
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37 | #ifndef BITHENGE_BLOB_H_
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38 | #define BITHENGE_BLOB_H_
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39 |
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40 | #include <sys/types.h>
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41 | #include "tree.h"
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42 |
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43 | /** A blob of raw binary data.
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44 | * @implements bithenge_node_t */
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45 | typedef struct {
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46 | /** @privatesection */
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47 | struct bithenge_node_t base;
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48 | } bithenge_blob_t;
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49 |
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50 | /** Operations providing random access to binary data.
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51 | * @todo Should these be thread-safe? */
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52 | typedef struct bithenge_random_access_blob_ops_t {
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53 | /** @copydoc bithenge_blob_t::bithenge_blob_size */
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54 | int (*size)(bithenge_blob_t *blob, aoff64_t *size);
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55 | /** @copydoc bithenge_blob_t::bithenge_blob_read */
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56 | int (*read)(bithenge_blob_t *blob, aoff64_t offset, char *buffer,
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57 | aoff64_t *size);
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58 | /** Destroy the blob.
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59 | * @param blob The blob.
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60 | * @return EOK on success or an error code from errno.h. */
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61 | int (*destroy)(bithenge_blob_t *blob);
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62 | } bithenge_random_access_blob_ops_t;
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63 |
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64 | /** A blob built from an object that supports only sequential reading.
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65 | * @implements bithenge_blob_t */
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66 | typedef struct {
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67 | /** @privatesection */
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68 | /** The base random-access blob. */
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69 | bithenge_blob_t base;
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70 | /** Operations providing sequential access. */
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71 | const struct bithenge_sequential_blob_ops_t *ops;
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72 | /** Buffer containing all data read. */
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73 | char *buffer;
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74 | /** Size of buffer. */
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75 | aoff64_t buffer_size;
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76 | /** Amount of data actually in buffer. */
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77 | aoff64_t data_size;
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78 | } bithenge_sequential_blob_t;
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79 |
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80 | /** Operations providing sequential access to binary data.
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81 | * @memberof bithenge_sequential_blob_t */
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82 | typedef struct bithenge_sequential_blob_ops_t {
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83 |
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84 | /** Get the total size of the blob. If the total size cannot be
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85 | * determined easily, this field may be null or return an error,
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86 | * forcing the entire blob to be read to determine its size.
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87 | *
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88 | * @memberof bithenge_blob_t
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89 | * @param blob The blob.
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90 | * @param[out] size Total size of the blob.
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91 | * @return EOK on success or an error code from errno.h.
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92 | */
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93 | int (*size)(bithenge_sequential_blob_t *blob, aoff64_t *size);
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94 |
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95 | /** Read the next part of the blob. If the requested data extends
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96 | * beyond the end of the blob, the data up until the end of the blob
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97 | * will be read.
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98 | *
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99 | * @param blob The blob.
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100 | * @param[out] buffer Buffer to read into. If an error occurs, the contents are
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101 | * undefined.
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102 | * @param[in,out] size Number of bytes to read; may be 0. If not enough
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103 | * data is left in the blob, the actual number of bytes read should be
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104 | * stored here. If an error occurs, the contents are undefined.
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105 | * @return EOK on success or an error code from errno.h.
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106 | */
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107 | int (*read)(bithenge_sequential_blob_t *blob, char *buffer,
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108 | aoff64_t *size);
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109 |
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110 | /** Destroy the blob.
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111 | * @param blob The blob.
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112 | * @return EOK on success or an error code from errno.h. */
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113 | int (*destroy)(bithenge_sequential_blob_t *blob);
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114 | } bithenge_sequential_blob_ops_t;
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115 |
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116 | /** Get the total size of the blob.
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117 | *
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118 | * @memberof bithenge_blob_t
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119 | * @param blob The blob.
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120 | * @param[out] size Total size of the blob.
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121 | * @return EOK on success or an error code from errno.h.
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122 | */
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123 | static inline int bithenge_blob_size(bithenge_blob_t *blob, aoff64_t *size)
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124 | {
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125 | assert(blob);
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126 | assert(blob->base.blob_ops);
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127 | return blob->base.blob_ops->size(blob, size);
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128 | }
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129 |
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130 | /** Read part of the blob. If the requested data extends beyond the end of the
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131 | * blob, the data up until the end of the blob will be read. If the offset is
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132 | * beyond the end of the blob, even if the size is zero, an error will be
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133 | * returned.
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134 | *
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135 | * @memberof bithenge_blob_t
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136 | * @param blob The blob.
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137 | * @param offset Byte offset within the blob.
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138 | * @param[out] buffer Buffer to read into. If an error occurs, the contents are
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139 | * undefined.
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140 | * @param[in,out] size Number of bytes to read; may be 0. If the requested
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141 | * range extends beyond the end of the blob, the actual number of bytes read
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142 | * should be stored here. If an error occurs, the contents are undefined.
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143 | * @return EOK on success or an error code from errno.h.
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144 | */
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145 | static inline int bithenge_blob_read(bithenge_blob_t *blob, aoff64_t offset,
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146 | char *buffer, aoff64_t *size)
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147 | {
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148 | assert(blob);
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149 | assert(blob->base.blob_ops);
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150 | return blob->base.blob_ops->read(blob, offset, buffer, size);
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151 | }
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152 |
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153 | /** Cast a blob node to a generic node.
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154 | * @memberof bithenge_blob_t
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155 | * @param blob The blob to cast.
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156 | * @return The blob node as a generic node. */
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157 | static inline bithenge_node_t *bithenge_blob_as_node(bithenge_blob_t *blob)
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158 | {
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159 | return &blob->base;
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160 | }
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161 |
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162 | /** Cast a generic node to a blob node.
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163 | * @memberof bithenge_blob_t
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164 | * @param node The node to cast, which must be a blob node.
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165 | * @return The generic node as a blob node. */
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166 | static inline bithenge_blob_t *bithenge_node_as_blob(bithenge_node_t *node)
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167 | {
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168 | assert(node->type == BITHENGE_NODE_BLOB);
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169 | return (bithenge_blob_t *)node;
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170 | }
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171 |
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172 | int bithenge_new_random_access_blob(bithenge_blob_t *blob,
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173 | const bithenge_random_access_blob_ops_t *ops);
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174 |
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175 | int bithenge_new_sequential_blob(bithenge_sequential_blob_t *blob,
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176 | const bithenge_sequential_blob_ops_t *ops);
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177 |
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178 | int bithenge_new_blob_from_data(bithenge_node_t **out, const void *data,
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179 | size_t len);
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180 |
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181 | int bithenge_new_blob_from_buffer(bithenge_node_t **out, const void *buffer,
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182 | size_t len, bool needs_free);
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183 |
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184 | bool bithenge_blob_equal(bithenge_blob_t *a, bithenge_blob_t *b);
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185 |
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186 | #endif
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187 |
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188 | /** @}
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189 | */
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