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
|
#pragma once
#include <stddef.h>
#include <stdint.h>
#ifdef __cplusplus
extern "C" {
#endif
/** \brief Puzzle bus message (v1) */
struct pb_msg {
uint16_t addr; //!< I^2^C address
char * data; //!< message content
size_t length; //!< message size
size_t _rdata; //!< \private remaining bytes to read until message is complete
};
/**
* \brief Read chunk of input stream, and store resulting message in \p target
*
* This function is called for each chunk of data from an input stream, and
* will parse the next puzzle bus message into \p target. The input stream is
* assumed to only contain messages encoded by \p pb_write()
*
* \param target pointer to struct that will contain the finished message data
* \param buf pointer to input stream data chunk
* \param buf_sz size of \p buf
*
* \returns Integer representing amount of bytes required to finish message, or
* -1 if the message header could not be read. If this function returns 0, the
* message in \p target is complete.
*
* \note target->data will automatically be allocated by this function, even if
* the message is not fully parsed. This variable must be `free()`d by the
* caller after each complete message to prevent memory leaks.
*/
int pb_read(struct pb_msg * target, const char * buf, size_t buf_sz);
/**
* \brief reset the remaining message data counter
*
* Calling this function has the effect of forcing \c pb_read() to parse the
* next buffer chunk as the start of a new message. This function may be called
* before reading a TCP frame's data to mitigate any synchronization issues
* arising from earlier corrupt or otherwise malformed messages.
*/
void pb_read_reset(struct pb_msg * target);
/**
* \brief Allocate and write a msgpack-formatted message to \p buf
*
* This function allocates a buffer large enough to fit the message specified
* in \p target, and encodes the data in \p target in a format that can be
* decoded later using \p pb_read()
*
* \param target pointer to struct that contains the message data
* \param buf pointer to \c char* that will contain the formatted message
* \param buf_sz pointer to \c size_t that will represent the final size of \p buf
*
* \returns boolean true if a the message could be encoded successfully, false
* if there was some kind of error
*
* \note the pointer stored in \p buf must be `free()`d by the caller afterwards
*/
bool pb_write(const struct pb_msg * target, char ** buf, size_t * buf_sz);
/**
* \brief I^2^C puzzle bus command types
*
* The first byte of a puzzle bus message's data indicates the command type.
*/
enum pb_cmd {
PB_CMD_READ, //!< read a puzzle module property
PB_CMD_WRITE, //!< write to a puzzle module property
// PB_CMD_UPDATE, //!< request an update
};
/** \brief Puzzle bus global states */
enum pb_global_state {
PB_GS_NOINIT, //!< uninitialized (only used by puzzle modules)
PB_GS_IDLE, //!< puzzle not started yet
PB_GS_PLAYING, //!< puzzle actively being solved
PB_GS_SOLVED, //!< puzzle completed
};
#ifdef __cplusplus
}
#endif
|