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#include "ngtcp2_rob.h"
26
27#include <string.h>
28#include <assert.h>
29
30#include "ngtcp2_macro.h"
31
32int ngtcp2_rob_gap_new(ngtcp2_rob_gap **pg, uint64_t begin, uint64_t end,
33                       const ngtcp2_mem *mem) {
34  *pg = ngtcp2_mem_malloc(mem, sizeof(ngtcp2_rob_gap));
35  if (*pg == NULL) {
36    return NGTCP2_ERR_NOMEM;
37  }
38
39  (*pg)->range.begin = begin;
40  (*pg)->range.end = end;
41
42  return 0;
43}
44
45void ngtcp2_rob_gap_del(ngtcp2_rob_gap *g, const ngtcp2_mem *mem) {
46  ngtcp2_mem_free(mem, g);
47}
48
49int ngtcp2_rob_data_new(ngtcp2_rob_data **pd, uint64_t offset, size_t chunk,
50                        const ngtcp2_mem *mem) {
51  *pd = ngtcp2_mem_malloc(mem, sizeof(ngtcp2_rob_data) + chunk);
52  if (*pd == NULL) {
53    return NGTCP2_ERR_NOMEM;
54  }
55
56  (*pd)->range.begin = offset;
57  (*pd)->range.end = offset + chunk;
58  (*pd)->begin = (uint8_t *)(*pd) + sizeof(ngtcp2_rob_data);
59  (*pd)->end = (*pd)->begin + chunk;
60
61  return 0;
62}
63
64void ngtcp2_rob_data_del(ngtcp2_rob_data *d, const ngtcp2_mem *mem) {
65  ngtcp2_mem_free(mem, d);
66}
67
68int ngtcp2_rob_init(ngtcp2_rob *rob, size_t chunk, const ngtcp2_mem *mem) {
69  int rv;
70  ngtcp2_rob_gap *g;
71
72  ngtcp2_ksl_init(&rob->gapksl, ngtcp2_ksl_range_compar, sizeof(ngtcp2_range),
73                  mem);
74
75  rv = ngtcp2_rob_gap_new(&g, 0, UINT64_MAX, mem);
76  if (rv != 0) {
77    goto fail_rob_gap_new;
78  }
79
80  rv = ngtcp2_ksl_insert(&rob->gapksl, NULL, &g->range, g);
81  if (rv != 0) {
82    goto fail_gapksl_ksl_insert;
83  }
84
85  ngtcp2_ksl_init(&rob->dataksl, ngtcp2_ksl_range_compar, sizeof(ngtcp2_range),
86                  mem);
87
88  rob->chunk = chunk;
89  rob->mem = mem;
90
91  return 0;
92
93fail_gapksl_ksl_insert:
94  ngtcp2_rob_gap_del(g, mem);
95fail_rob_gap_new:
96  ngtcp2_ksl_free(&rob->gapksl);
97  return rv;
98}
99
100void ngtcp2_rob_free(ngtcp2_rob *rob) {
101  ngtcp2_ksl_it it;
102
103  if (rob == NULL) {
104    return;
105  }
106
107  for (it = ngtcp2_ksl_begin(&rob->dataksl); !ngtcp2_ksl_it_end(&it);
108       ngtcp2_ksl_it_next(&it)) {
109    ngtcp2_rob_data_del(ngtcp2_ksl_it_get(&it), rob->mem);
110  }
111
112  for (it = ngtcp2_ksl_begin(&rob->gapksl); !ngtcp2_ksl_it_end(&it);
113       ngtcp2_ksl_it_next(&it)) {
114    ngtcp2_rob_gap_del(ngtcp2_ksl_it_get(&it), rob->mem);
115  }
116
117  ngtcp2_ksl_free(&rob->dataksl);
118  ngtcp2_ksl_free(&rob->gapksl);
119}
120
121static int rob_write_data(ngtcp2_rob *rob, uint64_t offset, const uint8_t *data,
122                          size_t len) {
123  size_t n;
124  int rv;
125  ngtcp2_rob_data *d;
126  ngtcp2_range range = {offset, offset + len};
127  ngtcp2_ksl_it it;
128
129  for (it = ngtcp2_ksl_lower_bound_compar(&rob->dataksl, &range,
130                                          ngtcp2_ksl_range_exclusive_compar);
131       len; ngtcp2_ksl_it_next(&it)) {
132    if (ngtcp2_ksl_it_end(&it)) {
133      d = NULL;
134    } else {
135      d = ngtcp2_ksl_it_get(&it);
136    }
137
138    if (d == NULL || offset < d->range.begin) {
139      rv = ngtcp2_rob_data_new(&d, (offset / rob->chunk) * rob->chunk,
140                               rob->chunk, rob->mem);
141      if (rv != 0) {
142        return rv;
143      }
144
145      rv = ngtcp2_ksl_insert(&rob->dataksl, &it, &d->range, d);
146      if (rv != 0) {
147        ngtcp2_rob_data_del(d, rob->mem);
148        return rv;
149      }
150    }
151
152    n = (size_t)ngtcp2_min((uint64_t)len, d->range.begin + rob->chunk - offset);
153    memcpy(d->begin + (offset - d->range.begin), data, n);
154    offset += n;
155    data += n;
156    len -= n;
157  }
158
159  return 0;
160}
161
162int ngtcp2_rob_push(ngtcp2_rob *rob, uint64_t offset, const uint8_t *data,
163                    size_t datalen) {
164  int rv;
165  ngtcp2_rob_gap *g;
166  ngtcp2_range m, l, r, q = {offset, offset + datalen};
167  ngtcp2_ksl_it it;
168
169  it = ngtcp2_ksl_lower_bound_compar(&rob->gapksl, &q,
170                                     ngtcp2_ksl_range_exclusive_compar);
171
172  for (; !ngtcp2_ksl_it_end(&it);) {
173    g = ngtcp2_ksl_it_get(&it);
174
175    m = ngtcp2_range_intersect(&q, &g->range);
176    if (!ngtcp2_range_len(&m)) {
177      break;
178    }
179    if (ngtcp2_range_eq(&g->range, &m)) {
180      ngtcp2_ksl_remove_hint(&rob->gapksl, &it, &it, &g->range);
181      ngtcp2_rob_gap_del(g, rob->mem);
182      rv = rob_write_data(rob, m.begin, data + (m.begin - offset),
183                          (size_t)ngtcp2_range_len(&m));
184      if (rv != 0) {
185        return rv;
186      }
187
188      continue;
189    }
190    ngtcp2_range_cut(&l, &r, &g->range, &m);
191    if (ngtcp2_range_len(&l)) {
192      ngtcp2_ksl_update_key(&rob->gapksl, &g->range, &l);
193      g->range = l;
194
195      if (ngtcp2_range_len(&r)) {
196        ngtcp2_rob_gap *ng;
197        rv = ngtcp2_rob_gap_new(&ng, r.begin, r.end, rob->mem);
198        if (rv != 0) {
199          return rv;
200        }
201        rv = ngtcp2_ksl_insert(&rob->gapksl, &it, &ng->range, ng);
202        if (rv != 0) {
203          ngtcp2_rob_gap_del(ng, rob->mem);
204          return rv;
205        }
206      }
207    } else if (ngtcp2_range_len(&r)) {
208      ngtcp2_ksl_update_key(&rob->gapksl, &g->range, &r);
209      g->range = r;
210    }
211    rv = rob_write_data(rob, m.begin, data + (m.begin - offset),
212                        (size_t)ngtcp2_range_len(&m));
213    if (rv != 0) {
214      return rv;
215    }
216    ngtcp2_ksl_it_next(&it);
217  }
218  return 0;
219}
220
221int ngtcp2_rob_remove_prefix(ngtcp2_rob *rob, uint64_t offset) {
222  ngtcp2_rob_gap *g;
223  ngtcp2_rob_data *d;
224  ngtcp2_ksl_it it;
225
226  it = ngtcp2_ksl_begin(&rob->gapksl);
227
228  for (; !ngtcp2_ksl_it_end(&it);) {
229    g = ngtcp2_ksl_it_get(&it);
230    if (offset <= g->range.begin) {
231      break;
232    }
233    if (offset < g->range.end) {
234      ngtcp2_range r = {offset, g->range.end};
235      ngtcp2_ksl_update_key(&rob->gapksl, &g->range, &r);
236      g->range.begin = offset;
237      break;
238    }
239    ngtcp2_ksl_remove_hint(&rob->gapksl, &it, &it, &g->range);
240    ngtcp2_rob_gap_del(g, rob->mem);
241  }
242
243  it = ngtcp2_ksl_begin(&rob->dataksl);
244
245  for (; !ngtcp2_ksl_it_end(&it);) {
246    d = ngtcp2_ksl_it_get(&it);
247    if (offset < d->range.begin + rob->chunk) {
248      return 0;
249    }
250    ngtcp2_ksl_remove_hint(&rob->dataksl, &it, &it, &d->range);
251    ngtcp2_rob_data_del(d, rob->mem);
252  }
253
254  return 0;
255}
256
257size_t ngtcp2_rob_data_at(ngtcp2_rob *rob, const uint8_t **pdest,
258                          uint64_t offset) {
259  ngtcp2_rob_gap *g;
260  ngtcp2_rob_data *d;
261  ngtcp2_ksl_it it;
262
263  it = ngtcp2_ksl_begin(&rob->gapksl);
264  if (ngtcp2_ksl_it_end(&it)) {
265    return 0;
266  }
267
268  g = ngtcp2_ksl_it_get(&it);
269
270  if (g->range.begin <= offset) {
271    return 0;
272  }
273
274  it = ngtcp2_ksl_begin(&rob->dataksl);
275  d = ngtcp2_ksl_it_get(&it);
276
277  assert(d);
278  assert(d->range.begin <= offset);
279  assert(offset < d->range.begin + rob->chunk);
280
281  *pdest = d->begin + (offset - d->range.begin);
282
283  return (size_t)(ngtcp2_min(g->range.begin, d->range.begin + rob->chunk) -
284                  offset);
285}
286
287void ngtcp2_rob_pop(ngtcp2_rob *rob, uint64_t offset, size_t len) {
288  ngtcp2_ksl_it it;
289  ngtcp2_rob_data *d;
290
291  it = ngtcp2_ksl_begin(&rob->dataksl);
292  d = ngtcp2_ksl_it_get(&it);
293
294  assert(d);
295
296  if (offset + len < d->range.begin + rob->chunk) {
297    return;
298  }
299
300  ngtcp2_ksl_remove_hint(&rob->dataksl, NULL, &it, &d->range);
301  ngtcp2_rob_data_del(d, rob->mem);
302}
303
304uint64_t ngtcp2_rob_first_gap_offset(ngtcp2_rob *rob) {
305  ngtcp2_ksl_it it = ngtcp2_ksl_begin(&rob->gapksl);
306  ngtcp2_rob_gap *g;
307
308  if (ngtcp2_ksl_it_end(&it)) {
309    return UINT64_MAX;
310  }
311
312  g = ngtcp2_ksl_it_get(&it);
313
314  return g->range.begin;
315}
316
317int ngtcp2_rob_data_buffered(ngtcp2_rob *rob) {
318  return ngtcp2_ksl_len(&rob->dataksl) != 0;
319}
320