xref: /freebsd/contrib/jemalloc/src/buf_writer.c (revision c43cad87172039ccf38172129c79755ea79e6102)
1 #include "jemalloc/internal/jemalloc_preamble.h"
2 #include "jemalloc/internal/jemalloc_internal_includes.h"
3 
4 #include "jemalloc/internal/buf_writer.h"
5 #include "jemalloc/internal/malloc_io.h"
6 
7 static void *
8 buf_writer_allocate_internal_buf(tsdn_t *tsdn, size_t buf_len) {
9 #ifdef JEMALLOC_JET
10 	if (buf_len > SC_LARGE_MAXCLASS) {
11 		return NULL;
12 	}
13 #else
14 	assert(buf_len <= SC_LARGE_MAXCLASS);
15 #endif
16 	return iallocztm(tsdn, buf_len, sz_size2index(buf_len), false, NULL,
17 	    true, arena_get(tsdn, 0, false), true);
18 }
19 
20 static void
21 buf_writer_free_internal_buf(tsdn_t *tsdn, void *buf) {
22 	if (buf != NULL) {
23 		idalloctm(tsdn, buf, NULL, NULL, true, true);
24 	}
25 }
26 
27 static void
28 buf_writer_assert(buf_writer_t *buf_writer) {
29 	assert(buf_writer != NULL);
30 	assert(buf_writer->write_cb != NULL);
31 	if (buf_writer->buf != NULL) {
32 		assert(buf_writer->buf_size > 0);
33 	} else {
34 		assert(buf_writer->buf_size == 0);
35 		assert(buf_writer->internal_buf);
36 	}
37 	assert(buf_writer->buf_end <= buf_writer->buf_size);
38 }
39 
40 bool
41 buf_writer_init(tsdn_t *tsdn, buf_writer_t *buf_writer, write_cb_t *write_cb,
42     void *cbopaque, char *buf, size_t buf_len) {
43 	if (write_cb != NULL) {
44 		buf_writer->write_cb = write_cb;
45 	} else {
46 		buf_writer->write_cb = je_malloc_message != NULL ?
47 		    je_malloc_message : wrtmessage;
48 	}
49 	buf_writer->cbopaque = cbopaque;
50 	assert(buf_len >= 2);
51 	if (buf != NULL) {
52 		buf_writer->buf = buf;
53 		buf_writer->internal_buf = false;
54 	} else {
55 		buf_writer->buf = buf_writer_allocate_internal_buf(tsdn,
56 		    buf_len);
57 		buf_writer->internal_buf = true;
58 	}
59 	if (buf_writer->buf != NULL) {
60 		buf_writer->buf_size = buf_len - 1; /* Allowing for '\0'. */
61 	} else {
62 		buf_writer->buf_size = 0;
63 	}
64 	buf_writer->buf_end = 0;
65 	buf_writer_assert(buf_writer);
66 	return buf_writer->buf == NULL;
67 }
68 
69 void
70 buf_writer_flush(buf_writer_t *buf_writer) {
71 	buf_writer_assert(buf_writer);
72 	if (buf_writer->buf == NULL) {
73 		return;
74 	}
75 	buf_writer->buf[buf_writer->buf_end] = '\0';
76 	buf_writer->write_cb(buf_writer->cbopaque, buf_writer->buf);
77 	buf_writer->buf_end = 0;
78 	buf_writer_assert(buf_writer);
79 }
80 
81 void
82 buf_writer_cb(void *buf_writer_arg, const char *s) {
83 	buf_writer_t *buf_writer = (buf_writer_t *)buf_writer_arg;
84 	buf_writer_assert(buf_writer);
85 	if (buf_writer->buf == NULL) {
86 		buf_writer->write_cb(buf_writer->cbopaque, s);
87 		return;
88 	}
89 	size_t i, slen, n;
90 	for (i = 0, slen = strlen(s); i < slen; i += n) {
91 		if (buf_writer->buf_end == buf_writer->buf_size) {
92 			buf_writer_flush(buf_writer);
93 		}
94 		size_t s_remain = slen - i;
95 		size_t buf_remain = buf_writer->buf_size - buf_writer->buf_end;
96 		n = s_remain < buf_remain ? s_remain : buf_remain;
97 		memcpy(buf_writer->buf + buf_writer->buf_end, s + i, n);
98 		buf_writer->buf_end += n;
99 		buf_writer_assert(buf_writer);
100 	}
101 	assert(i == slen);
102 }
103 
104 void
105 buf_writer_terminate(tsdn_t *tsdn, buf_writer_t *buf_writer) {
106 	buf_writer_assert(buf_writer);
107 	buf_writer_flush(buf_writer);
108 	if (buf_writer->internal_buf) {
109 		buf_writer_free_internal_buf(tsdn, buf_writer->buf);
110 	}
111 }
112 
113 void
114 buf_writer_pipe(buf_writer_t *buf_writer, read_cb_t *read_cb,
115     void *read_cbopaque) {
116 	/*
117 	 * A tiny local buffer in case the buffered writer failed to allocate
118 	 * at init.
119 	 */
120 	static char backup_buf[16];
121 	static buf_writer_t backup_buf_writer;
122 
123 	buf_writer_assert(buf_writer);
124 	assert(read_cb != NULL);
125 	if (buf_writer->buf == NULL) {
126 		buf_writer_init(TSDN_NULL, &backup_buf_writer,
127 		    buf_writer->write_cb, buf_writer->cbopaque, backup_buf,
128 		    sizeof(backup_buf));
129 		buf_writer = &backup_buf_writer;
130 	}
131 	assert(buf_writer->buf != NULL);
132 	ssize_t nread = 0;
133 	do {
134 		buf_writer->buf_end += nread;
135 		buf_writer_assert(buf_writer);
136 		if (buf_writer->buf_end == buf_writer->buf_size) {
137 			buf_writer_flush(buf_writer);
138 		}
139 		nread = read_cb(read_cbopaque,
140 		    buf_writer->buf + buf_writer->buf_end,
141 		    buf_writer->buf_size - buf_writer->buf_end);
142 	} while (nread > 0);
143 	buf_writer_flush(buf_writer);
144 }
145