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Format code with "make fmt" (indent must be installed).
1 parent 77aef64 commit 347e00b

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5 files changed

+291
-267
lines changed

5 files changed

+291
-267
lines changed

‎Makefile

Lines changed: 11 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -11,6 +11,17 @@ delay: $(OBJ)
1111

1212
$(OBJ): dtbuf.h time_ms.h
1313

14+
fmt:
15+
indent --linux-style \
16+
--indent-level4 \
17+
--no-tabs \
18+
--format-all-comments \
19+
--braces-on-if-line \
20+
--space-after-cast \
21+
*.c *.h
22+
# fix indent breaking pointer alignment on some function signatures
23+
find -name '*.[ch]' -exec sed -i '/^[a-z].*(.*)$$/s/ \* / */' {} ';'
24+
1425
clean:
1526
rm -f $(OBJ) $(OUT)
1627

‎dtbuf.c

Lines changed: 92 additions & 86 deletions
Original file line numberDiff line numberDiff line change
@@ -7,109 +7,115 @@
77
#define DTBUF_CHUNK_PAYLOAD_SIZE 4000
88

99
struct header {
10-
time_ms timestamp;
11-
chunk_length data_length;
10+
time_ms timestamp;
11+
chunk_length data_length;
1212
};
1313

1414
#define DTBUF_CHUNK_SIZE (sizeof (struct header) + DTBUF_CHUNK_PAYLOAD_SIZE)
1515

16-
int dtbuf_init(struct dtbuf *dtbuf, size_t capacity) {
17-
// to avoid splitting a chunk on the circular buffer boundaries, add
18-
// (DTBUF_CHUNK_SIZE-1) bytes at the end: a chunk starting at (capacity-1)
19-
// will still fit
20-
dtbuf->real_capacity = capacity + DTBUF_CHUNK_SIZE - 1;
21-
if (!(dtbuf->data = malloc(dtbuf->real_capacity))) {
22-
return 1;
23-
}
24-
dtbuf->capacity = capacity;
25-
dtbuf->head = 0;
26-
dtbuf->tail = 0;
27-
return 0;
16+
int dtbuf_init(struct dtbuf *dtbuf, size_t capacity)
17+
{
18+
// to avoid splitting a chunk on the circular buffer boundaries, add
19+
// (DTBUF_CHUNK_SIZE-1) bytes at the end: a chunk starting at (capacity-1)
20+
// will still fit
21+
dtbuf->real_capacity = capacity + DTBUF_CHUNK_SIZE - 1;
22+
if (!(dtbuf->data = malloc(dtbuf->real_capacity))) {
23+
return 1;
24+
}
25+
dtbuf->capacity = capacity;
26+
dtbuf->head = 0;
27+
dtbuf->tail = 0;
28+
return 0;
2829
}
2930

30-
void dtbuf_free(struct dtbuf *dtbuf) {
31-
free(dtbuf->data);
31+
void dtbuf_free(struct dtbuf *dtbuf)
32+
{
33+
free(dtbuf->data);
3234
}
3335

34-
int dtbuf_is_empty(struct dtbuf *dtbuf) {
35-
return dtbuf->head == dtbuf->tail;
36+
int dtbuf_is_empty(struct dtbuf *dtbuf)
37+
{
38+
return dtbuf->head == dtbuf->tail;
3639
}
3740

38-
int dtbuf_is_full(struct dtbuf *dtbuf) {
39-
// When dtbuf->head >= dtbuf->capacity, it "cycles" (reset to 0) if and
40-
// only if there is enough space at the start for a full chunk.
41-
// Thus, if dtbuf->head has not cycled while it is after capacity, then the
42-
// buffer is full.
43-
// Else, if head >= tail, there is always enough space (by design).
44-
// Else (if head < tail), there is enough space only if dtbuf->tail is far
45-
// enough (ie we can put a full chunk at the start).
46-
return dtbuf->head >= dtbuf->capacity || (dtbuf->head < dtbuf->tail
47-
&& dtbuf->tail - dtbuf->head <=
48-
DTBUF_CHUNK_SIZE);
41+
int dtbuf_is_full(struct dtbuf *dtbuf)
42+
{
43+
// When dtbuf->head >= dtbuf->capacity, it "cycles" (reset to 0) if and
44+
// only if there is enough space at the start for a full chunk.
45+
// Thus, if dtbuf->head has not cycled while it is after capacity, then the
46+
// buffer is full.
47+
// Else, if head >= tail, there is always enough space (by design).
48+
// Else (if head < tail), there is enough space only if dtbuf->tail is far
49+
// enough (ie we can put a full chunk at the start).
50+
return dtbuf->head >= dtbuf->capacity || (dtbuf->head < dtbuf->tail
51+
&& dtbuf->tail - dtbuf->head <=
52+
DTBUF_CHUNK_SIZE);
4953
}
5054

51-
time_ms dtbuf_next_timestamp(struct dtbuf *dtbuf) {
52-
struct header *header = (struct header *) &dtbuf->data[dtbuf->tail];
53-
return header->timestamp;
55+
time_ms dtbuf_next_timestamp(struct dtbuf *dtbuf)
56+
{
57+
struct header *header = (struct header *) &dtbuf->data[dtbuf->tail];
58+
return header->timestamp;
5459
}
5560

56-
ssize_t dtbuf_write_chunk(struct dtbuf *dtbuf, int fd_in, time_ms timestamp) {
57-
ssize_t r;
58-
struct header header;
59-
// directly write to dtbuf, at the right index
60-
int payload_index = dtbuf->head + sizeof(struct header);
61-
if ((r =
62-
read(fd_in, &dtbuf->data[payload_index],
63-
DTBUF_CHUNK_PAYLOAD_SIZE)) > 0) {
64-
// write headers
65-
header.timestamp = timestamp;
66-
header.data_length = (chunk_length) r;
67-
memcpy(&dtbuf->data[dtbuf->head], &header, sizeof(header));
68-
dtbuf->head = payload_index + r;
69-
if (dtbuf->head >= dtbuf->capacity && dtbuf->tail >= DTBUF_CHUNK_SIZE) {
70-
// not enough space at the end of the buffer, cycle if there is enough
71-
// at the start
72-
dtbuf->head = 0;
61+
ssize_t dtbuf_write_chunk(struct dtbuf *dtbuf, int fd_in, time_ms timestamp)
62+
{
63+
ssize_t r;
64+
struct header header;
65+
// directly write to dtbuf, at the right index
66+
int payload_index = dtbuf->head + sizeof(struct header);
67+
if ((r = read(fd_in, &dtbuf->data[payload_index],
68+
DTBUF_CHUNK_PAYLOAD_SIZE)) > 0) {
69+
// write headers
70+
header.timestamp = timestamp;
71+
header.data_length = (chunk_length) r;
72+
memcpy(&dtbuf->data[dtbuf->head], &header, sizeof(header));
73+
dtbuf->head = payload_index + r;
74+
if (dtbuf->head >= dtbuf->capacity && dtbuf->tail >= DTBUF_CHUNK_SIZE) {
75+
// not enough space at the end of the buffer, cycle if there is
76+
// enough at the start
77+
dtbuf->head = 0;
78+
}
79+
} else if (r == -1) {
80+
perror("read()");
7381
}
74-
} else if (r == -1) {
75-
perror("read()");
76-
}
77-
return r;
82+
return r;
7883
}
7984

80-
ssize_t dtbuf_read_chunk(struct dtbuf * dtbuf, int fd_out) {
81-
ssize_t w;
82-
struct header *pheader = (struct header *) &dtbuf->data[dtbuf->tail];
83-
struct header header;
84-
chunk_length length = pheader->data_length;
85-
// directly read from dtbuf, at the right index
86-
int payload_index = dtbuf->tail + sizeof(struct header);
87-
if ((w = write(fd_out, &dtbuf->data[payload_index], length)) > 0) {
88-
if (w == length) {
89-
// we succeed to write all the data
90-
dtbuf->tail = payload_index + w;
91-
if (dtbuf->tail >= dtbuf->capacity) {
92-
// the next chunk cannot be after capacity
93-
dtbuf->tail = 0;
94-
if (dtbuf->head >= dtbuf->capacity) {
95-
// can happen if capacity < DTBUF_CHUNK_SIZE
96-
dtbuf->head = 0;
85+
ssize_t dtbuf_read_chunk(struct dtbuf *dtbuf, int fd_out)
86+
{
87+
ssize_t w;
88+
struct header *pheader = (struct header *) &dtbuf->data[dtbuf->tail];
89+
struct header header;
90+
chunk_length length = pheader->data_length;
91+
// directly read from dtbuf, at the right index
92+
int payload_index = dtbuf->tail + sizeof(struct header);
93+
if ((w = write(fd_out, &dtbuf->data[payload_index], length)) > 0) {
94+
if (w == length) {
95+
// we succeed to write all the data
96+
dtbuf->tail = payload_index + w;
97+
if (dtbuf->tail >= dtbuf->capacity) {
98+
// the next chunk cannot be after capacity
99+
dtbuf->tail = 0;
100+
if (dtbuf->head >= dtbuf->capacity) {
101+
// can happen if capacity < DTBUF_CHUNK_SIZE
102+
dtbuf->head = 0;
103+
}
104+
}
105+
} else {
106+
dtbuf->tail += w;
107+
// set the timestamp for writing at the new tail position
108+
header.timestamp = pheader->timestamp;
109+
// set the remaining length
110+
header.data_length = length - w;
111+
memcpy(&dtbuf->data[dtbuf->tail], &header, sizeof(header));
97112
}
98-
}
99-
} else {
100-
dtbuf->tail += w;
101-
// set the timestamp for writing at the new tail position
102-
header.timestamp = pheader->timestamp;
103-
// set the remaining length
104-
header.data_length = length - w;
105-
memcpy(&dtbuf->data[dtbuf->tail], &header, sizeof(header));
106-
}
107-
if (dtbuf->head >= dtbuf->capacity && dtbuf->tail >= DTBUF_CHUNK_SIZE) {
108-
// there is enough space at the start now, head can cycle
109-
dtbuf->head = 0;
113+
if (dtbuf->head >= dtbuf->capacity && dtbuf->tail >= DTBUF_CHUNK_SIZE) {
114+
// there is enough space at the start now, head can cycle
115+
dtbuf->head = 0;
116+
}
117+
} else if (w == -1) {
118+
perror("write()");
110119
}
111-
} else if (w == -1) {
112-
perror("write()");
113-
}
114-
return w;
120+
return w;
115121
}

‎dtbuf.h

Lines changed: 5 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -22,11 +22,11 @@
2222
typedef uint16_t chunk_length;
2323

2424
struct dtbuf {
25-
char *data;
26-
size_t capacity; // expected capacity
27-
size_t real_capacity; // capacity + DTBUF_CHUNK_SIZE - 1
28-
int head; // index of the next chunk
29-
int tail; // index of the oldest chunk in memory
25+
char *data;
26+
size_t capacity; // expected capacity
27+
size_t real_capacity; // capacity + DTBUF_CHUNK_SIZE - 1
28+
int head; // index of the next chunk
29+
int tail; // index of the oldest chunk in memory
3030
};
3131

3232
// init a dtbuf structure with an expected capacity

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