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1 /*
2  * ngtcp2
3  *
4  * Copyright (c) 2017 ngtcp2 contributors
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining
7  * a copy of this software and associated documentation files (the
8  * "Software"), to deal in the Software without restriction, including
9  * without limitation the rights to use, copy, modify, merge, publish,
10  * distribute, sublicense, and/or sell copies of the Software, and to
11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be
15  * included in all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
20  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
21  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
22  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
23  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24  */
25 #ifndef NGTCP2_ROB_H
26 #define NGTCP2_ROB_H
27 
28 #ifdef HAVE_CONFIG_H
29 #  include <config.h>
30 #endif /* HAVE_CONFIG_H */
31 
32 #include <ngtcp2/ngtcp2.h>
33 
34 #include "ngtcp2_mem.h"
35 #include "ngtcp2_range.h"
36 #include "ngtcp2_ksl.h"
37 
38 /*
39  * ngtcp2_rob_gap represents the gap, which is the range of stream
40  * data that is not received yet.
41  */
42 typedef struct ngtcp2_rob_gap {
43   /* range is the range of this gap. */
44   ngtcp2_range range;
45 } ngtcp2_rob_gap;
46 
47 /*
48  * ngtcp2_rob_gap_new allocates new ngtcp2_rob_gap object, and assigns
49  * its pointer to |*pg|.  The caller should call ngtcp2_rob_gap_del to
50  * delete it when it is no longer used.  The range of the gap is
51  * [begin, end).  |mem| is custom memory allocator to allocate memory.
52  *
53  * This function returns 0 if it succeeds, or one of the following
54  * negative error codes:
55  *
56  * NGTCP2_ERR_NOMEM
57  *     Out of memory.
58  */
59 int ngtcp2_rob_gap_new(ngtcp2_rob_gap **pg, uint64_t begin, uint64_t end,
60                        const ngtcp2_mem *mem);
61 
62 /*
63  * ngtcp2_rob_gap_del deallocates |g|.  It deallocates the memory
64  * pointed by |g| it self.  |mem| is custom memory allocator to
65  * deallocate memory.
66  */
67 void ngtcp2_rob_gap_del(ngtcp2_rob_gap *g, const ngtcp2_mem *mem);
68 
69 /*
70  * ngtcp2_rob_data holds the buffered stream data.
71  */
72 typedef struct ngtcp2_rob_data {
73   /* range is the range of this gap. */
74   ngtcp2_range range;
75   /* begin points to the buffer. */
76   uint8_t *begin;
77   /* end points to the one beyond of the last byte of the buffer */
78   uint8_t *end;
79 } ngtcp2_rob_data;
80 
81 /*
82  * ngtcp2_rob_data_new allocates new ngtcp2_rob_data object, and
83  * assigns its pointer to |*pd|.  The caller should call
84  * ngtcp2_rob_data_del to delete it when it is no longer used.
85  * |offset| is the stream offset of the first byte of this data.
86  * |chunk| is the size of the buffer.  |offset| must be multiple of
87  * |chunk|.  |mem| is custom memory allocator to allocate memory.
88  *
89  * This function returns 0 if it succeeds, or one of the following
90  * negative error codes:
91  *
92  * NGTCP2_ERR_NOMEM
93  *     Out of memory.
94  */
95 int ngtcp2_rob_data_new(ngtcp2_rob_data **pd, uint64_t offset, size_t chunk,
96                         const ngtcp2_mem *mem);
97 
98 /*
99  * ngtcp2_rob_data_del deallocates |d|.  It deallocates the memory
100  * pointed by |d| itself.  |mem| is custom memory allocator to
101  * deallocate memory.
102  */
103 void ngtcp2_rob_data_del(ngtcp2_rob_data *d, const ngtcp2_mem *mem);
104 
105 /*
106  * ngtcp2_rob is the reorder buffer which reassembles stream data
107  * received in out of order.
108  */
109 typedef struct ngtcp2_rob {
110   /* gapksl maintains the range of offset which is not received
111      yet. Initially, its range is [0, UINT64_MAX). */
112   ngtcp2_ksl gapksl;
113   /* dataksl maintains the list of buffers which store received data
114      ordered by stream offset. */
115   ngtcp2_ksl dataksl;
116   /* mem is custom memory allocator */
117   const ngtcp2_mem *mem;
118   /* chunk is the size of each buffer in data field */
119   size_t chunk;
120 } ngtcp2_rob;
121 
122 /*
123  * ngtcp2_rob_init initializes |rob|.  |chunk| is the size of buffer
124  * per chunk.
125  *
126  * This function returns 0 if it succeeds, or one of the following
127  * negative error codes:
128  *
129  * NGTCP2_ERR_NOMEM
130  *     Out of memory.
131  */
132 int ngtcp2_rob_init(ngtcp2_rob *rob, size_t chunk, const ngtcp2_mem *mem);
133 
134 /*
135  * ngtcp2_rob_free frees resources allocated for |rob|.
136  */
137 void ngtcp2_rob_free(ngtcp2_rob *rob);
138 
139 /*
140  * ngtcp2_rob_push adds new data of length |datalen| at the stream
141  * offset |offset|.
142  *
143  * This function returns 0 if it succeeds, or one of the following
144  * negative error codes:
145  *
146  * NGTCP2_ERR_NOMEM
147  *     Out of memory
148  */
149 int ngtcp2_rob_push(ngtcp2_rob *rob, uint64_t offset, const uint8_t *data,
150                     size_t datalen);
151 
152 /*
153  * ngtcp2_rob_remove_prefix removes gap up to |offset|, exclusive.  It
154  * also removes data buffer if it is completely included in |offset|.
155  *
156  * This function returns 0 if it succeeds, or one of the following
157  * negative error codes:
158  *
159  * NGTCP2_ERR_NOMEM
160  *     Out of memory
161  */
162 int ngtcp2_rob_remove_prefix(ngtcp2_rob *rob, uint64_t offset);
163 
164 /*
165  * ngtcp2_rob_data_at stores the pointer to the buffer of stream
166  * offset |offset| to |*pdest| if it is available, and returns the
167  * valid length of available data.  If no data is available, it
168  * returns 0.
169  */
170 size_t ngtcp2_rob_data_at(ngtcp2_rob *rob, const uint8_t **pdest,
171                           uint64_t offset);
172 
173 /*
174  * ngtcp2_rob_pop clears data at stream offset |offset| of length
175  * |len|.
176  *
177  * |offset| must be the offset given in ngtcp2_rob_data_at.  |len|
178  * must be the return value of ngtcp2_rob_data_at when |offset| is
179  * passed.
180  *
181  * Caller should call this function from offset 0 in non-decreasing
182  * order.
183  */
184 void ngtcp2_rob_pop(ngtcp2_rob *rob, uint64_t offset, size_t len);
185 
186 /*
187  * ngtcp2_rob_first_gap_offset returns the offset to the first gap.
188  * If there is no gap, it returns UINT64_MAX.
189  */
190 uint64_t ngtcp2_rob_first_gap_offset(ngtcp2_rob *rob);
191 
192 /*
193  * ngtcp2_rob_data_buffered returns nonzero if any data is buffered.
194  */
195 int ngtcp2_rob_data_buffered(ngtcp2_rob *rob);
196 
197 #endif /* NGTCP2_ROB_H */
198