// processes an incoming byte in the midi state machine
void midi_msg_proc(uint8_t b)
{
bool is_status = ((b & 0x80) != 0);
// handle status byte
if (is_status) {
if (is_realtime(b)) {
// real-time, no data, process immediately
msg_handle_fn(b, NULL, 0);
} else {
// non real-time
idx = 0;
len = get_len(b);
status = b;
if (len == 0) {
// no data, process immediately
msg_handle_fn(status, NULL, len);
status = next_status(status);
}
}
return;
}
// handle data byte
if ((status > 0) && (len > 0)) {
if (idx < len) {
// store data byte
data[idx++] = b;
if (idx == len) {
idx = 0;
// process it
msg_handle_fn(status, data, len);
// prepare for next message
status = next_status(status);
}
} else {
// overrun, should never happen
}
} else {
// unexpected data, ignore it
}
}
int tokenize(struct token_list* tk_list, char* file_buffer)
{
enum Status status;
line_num;
size_t token_begin, token_end;
token_begin = 0, token_end = 0;
status = STATUS_INVALID;
str_toupper(file_buffer);
/*
* Careful: it seems an error to let "i <= len",
* but we need one more execution to flush the last token into token list.
*/
size_t line_num = 1;
for (size_t i = 0; ; ++i) {
struct token_node* tok_node;
switch (status) {
case STATUS_LETTER:
if (!IS_LETTER(file_buffer[i]) && !IS_DIGIT(file_buffer[i])) {
token_end = i;
tok_node = create_token(TOKEN_LABEL, file_buffer + token_begin, token_end - token_begin);
tok_node->type = letter_type(tok_node->liter, tok_node->len);
token_append(tk_list, tok_node);
token_begin = i;
status = next_status(status, file_buffer[i]);
}
break;
case STATUS_PRAGMA:
if (!IS_LETTER(file_buffer[i])) {
int type;
token_end = i;
type = pragma_type(file_buffer + token_begin, token_end - token_begin);
if (type < 0) {
error("invalid pragma ad line %d\n", line_num);
return -4;
}
tok_node = create_token(type, file_buffer + token_begin, token_end - token_begin);
token_append(tk_list, tok_node);
token_begin = i;
status = next_status(status, file_buffer[i]);
}
break;
case STATUS_PUNCTUATION:
token_end = i;
tok_node = create_token(file_buffer[token_begin], file_buffer + token_begin, token_end - token_begin);
token_append(tk_list, tok_node);
token_begin = i;
status = next_status(status, file_buffer[i]);
break;
case STATUS_NUMBER:
if (!IS_NUMBER(file_buffer[i])) {
token_end = i;
if (!check_number(file_buffer + token_begin, token_end - token_begin)) {
error("invalid number format at line %d\n", line_num);
return -2;
}
tok_node = create_token(TOKEN_NUMBER, file_buffer + token_begin, token_end - token_begin);
tok_node->data = parse_number(tok_node->liter);
token_append(tk_list, tok_node);
token_begin = i;
status = next_status(status, file_buffer[i]);
}
break;
case STATUS_BLANK:
if (!IS_BLANK(file_buffer[i])) {
token_begin = i;
status = next_status(status, file_buffer[i]);
}
break;
case STATUS_COMMENTS:
//once status is in comments, it will always be in comments
if ('\n' == file_buffer[i]) {
token_begin = i;
status = next_status(status, file_buffer[i]);
}
break;
case STATUS_INVALID:
token_begin = i;
status = next_status(status, file_buffer[i]);
if (STATUS_INVALID == status && 0 != file_buffer[i]) {
error("invalid format at line %d\n", line_num);
return -3;
}
break;
}
if (0 == file_buffer[i])
break;
else if ('\n' == file_buffer[i])
++line_num;
}
return 0;
}
