aboutsummaryrefslogtreecommitdiffstats
path: root/erts/emulator/beam/erl_io_queue.h
blob: 7d0fe6751c97bd3e597a48b8e0851fa72209b271 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
/*
 * %CopyrightBegin%
 * 
 * Copyright Ericsson AB 2017. All Rights Reserved.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 * %CopyrightEnd%
 */

/*
 * Description: A queue used for storing binary data that should be
 *              passed to writev or similar functions. Used by both
 *              the nif and driver api.
 *
 * Author:      Lukas Larsson
 */

#ifndef ERL_IO_QUEUE_H__TYPES__
#define ERL_IO_QUEUE_H__TYPES__

#define ERTS_BINARY_TYPES_ONLY__
#include "erl_binary.h"
#undef ERTS_BINARY_TYPES_ONLY__
#include "erl_nif.h"

#ifdef DEBUG
#define MAX_SYSIOVEC_IOVLEN (1ull << (32 - 1))
#else
#define MAX_SYSIOVEC_IOVLEN (1ull << (sizeof(((SysIOVec*)0)->iov_len) * 8 - 1))
#endif

#define ERTS_SMALL_IO_QUEUE 5

typedef union {
    ErlDrvBinary driver;
    Binary nif;
} ErtsIOQBinary;

typedef struct {
    int vsize;         /* length of vectors */
    Uint size;         /* total size in bytes */
    SysIOVec* iov;
    ErtsIOQBinary** binv;
} ErtsIOVecCommon;

typedef union {
    ErtsIOVecCommon common;
    ErlIOVec driver;
    ErlNifIOVec nif;
} ErtsIOVec;

/* head/tail represent the data in the queue
 * start/end represent the edges of the allocated queue
 * small is used when the number of iovec elements is < SMALL_IO_QUEUE
 */
typedef struct erts_io_queue {
    ErtsAlcType_t alct;
    int driver;
    Uint size;       /* total size in bytes */

    SysIOVec* v_start;
    SysIOVec* v_end;
    SysIOVec* v_head;
    SysIOVec* v_tail;
    SysIOVec  v_small[ERTS_SMALL_IO_QUEUE];

    ErtsIOQBinary **b_start;
    ErtsIOQBinary **b_end;
    ErtsIOQBinary **b_head;
    ErtsIOQBinary **b_tail;
    ErtsIOQBinary  *b_small[ERTS_SMALL_IO_QUEUE];

} ErtsIOQueue;

#endif /* ERL_IO_QUEUE_H__TYPES__ */

#if !defined(ERL_IO_QUEUE_H) && !defined(ERTS_IO_QUEUE_TYPES_ONLY__)
#define ERL_IO_QUEUE_H

#include "erl_binary.h"
#include "erl_bits.h"

void erts_ioq_init(ErtsIOQueue *q, ErtsAlcType_t alct, int driver);
void erts_ioq_clear(ErtsIOQueue *q);
Uint erts_ioq_size(ErtsIOQueue *q);
int erts_ioq_enqv(ErtsIOQueue *q, ErtsIOVec *vec, Uint skip);
int erts_ioq_pushqv(ErtsIOQueue *q, ErtsIOVec *vec, Uint skip);
int erts_ioq_deq(ErtsIOQueue *q, Uint Uint);
Uint erts_ioq_peekqv(ErtsIOQueue *q, ErtsIOVec *ev);
SysIOVec *erts_ioq_peekq(ErtsIOQueue *q, int *vlenp);
Uint erts_ioq_sizeq(ErtsIOQueue *q);

int erts_ioq_iolist_vec_len(Eterm obj, int* vsize, Uint* csize,
                            Uint* pvsize, Uint* pcsize,
                            size_t* total_size, Uint blimit);
int erts_ioq_iolist_to_vec(Eterm obj, SysIOVec* iov,
                           ErtsIOQBinary** binv, ErtsIOQBinary* cbin,
                           Uint bin_limit, int driver_binary);

ERTS_GLB_INLINE
int erts_ioq_iodata_vec_len(Eterm obj, int* vsize, Uint* csize,
                            Uint* pvsize, Uint* pcsize,
                            size_t* total_size, Uint blimit);
ERTS_GLB_INLINE
int erts_ioq_iodata_to_vec(Eterm obj, SysIOVec* iov,
                           ErtsIOQBinary** binv, ErtsIOQBinary* cbin,
                           Uint bin_limit, int driver_binary);


#if ERTS_GLB_INLINE_INCL_FUNC_DEF

ERTS_GLB_INLINE
int erts_ioq_iodata_vec_len(Eterm obj, int* vsize, Uint* csize,
                            Uint* pvsize, Uint* pcsize,
                            size_t* total_size, Uint blimit) {
  if (is_binary(obj)) {
    /* We optimize for when we get a procbin without a bit-offset
     * that fits in one iov slot
     */
    Eterm real_bin;
    byte bitoffs;
    byte bitsize;
    ERTS_DECLARE_DUMMY(Uint offset);
    Uint size = binary_size(obj);
    ERTS_GET_REAL_BIN(obj, real_bin, offset, bitoffs, bitsize);
    if (size < MAX_SYSIOVEC_IOVLEN && bitoffs == 0 && bitsize == 0) {
      *vsize = 1;
      *pvsize = 1;
      if (thing_subtag(*binary_val(real_bin)) == REFC_BINARY_SUBTAG) {
          *csize = 0;
          *pcsize = 0;
      } else {
          *csize = size;
          *pcsize = size;
      }
      *total_size = size;
      return 0;
    }
  }

  return erts_ioq_iolist_vec_len(obj, vsize, csize,
                                 pvsize, pcsize, total_size, blimit);
}

ERTS_GLB_INLINE
int erts_ioq_iodata_to_vec(Eterm obj,
                           SysIOVec *iov,
                           ErtsIOQBinary **binv,
                           ErtsIOQBinary  *cbin,
                           Uint bin_limit,
                           int driver)
{
    if (is_binary(obj)) {
        Eterm real_bin;
        byte bitoffs;
        byte bitsize;
        Uint offset;
        Uint size = binary_size(obj);
        ERTS_GET_REAL_BIN(obj, real_bin, offset, bitoffs, bitsize);
        if (size < MAX_SYSIOVEC_IOVLEN && bitoffs == 0 && bitsize == 0) {
            Eterm *bptr = binary_val(real_bin);
            if (thing_subtag(*bptr) == REFC_BINARY_SUBTAG) {
                ProcBin *pb = (ProcBin *)bptr;
                if (pb->flags)
                    erts_emasculate_writable_binary(pb);
                iov[0].iov_base = pb->bytes+offset;
                iov[0].iov_len = size;
                if (driver)
                    binv[0] = (ErtsIOQBinary*)Binary2ErlDrvBinary(pb->val);
                else
                    binv[0] = (ErtsIOQBinary*)pb->val;
                return 1;
            } else {
                ErlHeapBin* hb = (ErlHeapBin *)bptr;
                byte *buf = driver ? (byte*)cbin->driver.orig_bytes :
                    (byte*)cbin->nif.orig_bytes;
		copy_binary_to_buffer(buf, 0, ((byte *) hb->data)+offset, 0, 8*size);
                iov[0].iov_base = buf;
                iov[0].iov_len = size;
                binv[0] = cbin;
                return 1;
            }
        }
    }
    return erts_ioq_iolist_to_vec(obj, iov, binv, cbin, bin_limit, driver);
}

#endif

#endif /* ERL_IO_QUEUE_H */