2 This file is part of GNUnet.
3 (C) 2009 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
23 * @brief Merkle-tree-ish-CHK file encoding for GNUnet
24 * @see https://gnunet.org/encoding
25 * @author Krista Bennett
26 * @author Christian Grothoff
29 * - decide if this API should be made public (gnunet_fs_service.h)
30 * or remain "internal" (but with exported symbols?)
32 #ifndef GNUNET_FS_TREE_H
33 #define GNUNET_FS_TREE_H
38 * Compute the depth of the CHK tree.
40 * @param flen file length for which to compute the depth
41 * @return depth of the tree, always > 0. A depth of 1 means only a DBLOCK.
43 unsigned int GNUNET_FS_compute_depth (uint64_t flen);
47 * Calculate how many bytes of payload a block tree of the given
48 * depth MAY correspond to at most (this function ignores the fact that
49 * some blocks will only be present partially due to the total file
50 * size cutting some blocks off at the end).
52 * @param depth depth of the block. depth==0 is a DBLOCK.
53 * @return number of bytes of payload a subtree of this depth may correspond to
55 uint64_t GNUNET_FS_tree_compute_tree_size (unsigned int depth);
59 * Compute how many bytes of data should be stored in
60 * the specified block.
62 * @param fsize overall file size, must be > 0.
63 * @param offset offset in the original data corresponding
64 * to the beginning of the tree induced by the block;
66 * @param depth depth of the node in the tree, 0 for DBLOCK
67 * @return number of bytes stored in this node
69 size_t GNUNET_FS_tree_calculate_block_size (uint64_t fsize, uint64_t offset,
74 * Context for an ECRS-based file encoder that computes
75 * the Merkle-ish-CHK tree.
77 struct GNUNET_FS_TreeEncoder;
81 * Function called asking for the current (encoded)
82 * block to be processed. After processing the
83 * client should either call "GNUNET_FS_tree_encode_next"
84 * or (on error) "GNUNET_FS_tree_encode_finish".
87 * @param chk content hash key for the block
88 * @param offset offset of the block
89 * @param depth depth of the block, 0 for DBLOCKs
90 * @param type type of the block (IBLOCK or DBLOCK)
91 * @param block the (encrypted) block
92 * @param block_size size of block (in bytes)
94 typedef void (*GNUNET_FS_TreeBlockProcessor) (void *cls,
95 const struct ContentHashKey * chk,
98 enum GNUNET_BLOCK_Type type,
100 uint16_t block_size);
104 * Function called with information about our
105 * progress in computing the tree encoding.
108 * @param offset where are we in the file
109 * @param pt_block plaintext of the currently processed block
110 * @param pt_size size of pt_block
111 * @param depth depth of the block in the tree, 0 for DBLOCKS
113 typedef void (*GNUNET_FS_TreeProgressCallback) (void *cls, uint64_t offset,
114 const void *pt_block,
120 * Initialize a tree encoder. This function will call "proc" and
121 * "progress" on each block in the tree. Once all blocks have been
122 * processed, "cont" will be scheduled. The "reader" will be called
123 * to obtain the (plaintext) blocks for the file. Note that this
124 * function will actually never call "proc"; the "proc" function must
125 * be triggered by calling "GNUNET_FS_tree_encoder_next" to trigger
126 * encryption (and calling of "proc") for each block.
128 * @param h the global FS context
129 * @param size overall size of the file to encode
130 * @param cls closure for reader, proc, progress and cont
131 * @param reader function to call to read plaintext data
132 * @param proc function to call on each encrypted block
133 * @param progress function to call with progress information
134 * @param cont function to call when done
135 * @return tree encoder context
137 struct GNUNET_FS_TreeEncoder *GNUNET_FS_tree_encoder_create (struct
143 GNUNET_FS_TreeBlockProcessor
145 GNUNET_FS_TreeProgressCallback
147 GNUNET_SCHEDULER_Task
152 * Encrypt the next block of the file (and
153 * call proc and progress accordingly; or
154 * of course "cont" if we have already completed
155 * encoding of the entire file).
157 * @param te tree encoder to use
159 void GNUNET_FS_tree_encoder_next (struct GNUNET_FS_TreeEncoder *te);
163 * Clean up a tree encoder and return information
164 * about the resulting URI or an error message.
166 * @param te the tree encoder to clean up
167 * @param uri set to the resulting URI (if encoding finished)
168 * @param emsg set to an error message (if an error occured
169 * within the tree encoder; if this function is called
170 * prior to completion and prior to an internal error,
171 * both "*uri" and "*emsg" will be set to NULL).
173 void GNUNET_FS_tree_encoder_finish (struct GNUNET_FS_TreeEncoder *te,
174 struct GNUNET_FS_Uri **uri, char **emsg);
178 /* the functions below will be needed for persistence
179 but are not yet implemented -- FIXME... */
181 * Get data that would be needed to resume
182 * the encoding later.
184 * @param te encoding to resume
185 * @param data set to the resume data
186 * @param size set to the size of the resume data
188 void GNUNET_FS_tree_encoder_resume_get_data (const struct GNUNET_FS_TreeEncoder
189 *te, void **data, size_t * size);
193 * Reset tree encoder to point previously
194 * obtained for resuming.
196 * @param te encoding to resume
197 * @param data the resume data
198 * @param size the size of the resume data
200 void GNUNET_FS_tree_encoder_resume (struct GNUNET_FS_TreeEncoder *te,
201 const void *data, size_t size);
206 /* end of fs_tree.h */