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_GAPTR_H
26 #define NGTCP2_GAPTR_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_ksl.h"
36 
37 /*
38  * ngtcp2_gaptr maintains the gap in the range [0, UINT64_MAX).
39  */
40 typedef struct ngtcp2_gaptr {
41   /* gap maintains the range of offset which is not received
42      yet. Initially, its range is [0, UINT64_MAX). */
43   ngtcp2_ksl gap;
44   /* mem is custom memory allocator */
45   const ngtcp2_mem *mem;
46 } ngtcp2_gaptr;
47 
48 /*
49  * ngtcp2_gaptr_init initializes |gaptr|.
50  *
51  * This function returns 0 if it succeeds, or one of the following
52  * negative error codes:
53  *
54  * NGTCP2_ERR_NOMEM
55  *     Out of memory.
56  */
57 int ngtcp2_gaptr_init(ngtcp2_gaptr *gaptr, const ngtcp2_mem *mem);
58 
59 /*
60  * ngtcp2_gaptr_free frees resources allocated for |gaptr|.
61  */
62 void ngtcp2_gaptr_free(ngtcp2_gaptr *gaptr);
63 
64 /*
65  * ngtcp2_gaptr_push adds new data of length |datalen| at the stream
66  * offset |offset|.
67  *
68  * This function returns 0 if it succeeds, or one of the following
69  * negative error codes:
70  *
71  * NGTCP2_ERR_NOMEM
72  *     Out of memory
73  */
74 int ngtcp2_gaptr_push(ngtcp2_gaptr *gaptr, uint64_t offset, uint64_t datalen);
75 
76 /*
77  * ngtcp2_gaptr_first_gap_offset returns the offset to the first gap.
78  * If there is no gap, it returns UINT64_MAX.
79  */
80 uint64_t ngtcp2_gaptr_first_gap_offset(ngtcp2_gaptr *gaptr);
81 
82 /*
83  * ngtcp2_gaptr_get_first_gap_after returns the iterator pointing to
84  * the first gap which overlaps or comes after |offset|.
85  */
86 ngtcp2_ksl_it ngtcp2_gaptr_get_first_gap_after(ngtcp2_gaptr *gaptr,
87                                                uint64_t offset);
88 
89 /*
90  * ngtcp2_gaptr_is_pushed returns nonzero if range [offset, offset +
91  * datalen) is completely pushed into this object.
92  */
93 int ngtcp2_gaptr_is_pushed(ngtcp2_gaptr *gaptr, uint64_t offset,
94                            uint64_t datalen);
95 
96 /*
97  * ngtcp2_gaptr_drop_first_gap deletes the first gap entirely as if
98  * the range is pushed.  This function assumes that at least one gap
99  * exists.
100  */
101 void ngtcp2_gaptr_drop_first_gap(ngtcp2_gaptr *gaptr);
102 
103 #endif /* NGTCP2_GAPTR_H */
104