/**
* This method is used to read and consume the input buffer
* @arg conn The client connection
* @arg bytes The number of bytes to read
* @arg buf Output parameter, sets the start of the buffer.
* @arg should_free Output parameter, should the buffer be freed by the caller.
* @return 0 on success, -1 if there is insufficient data.
*/
int read_client_bytes(statsite_conn_info *conn, int bytes, char** buf, int* should_free) {
if (unlikely(bytes > circbuf_used_buf(&conn->input))) return -1;
// Handle the wrap around case
if (unlikely(conn->input.write_cursor < conn->input.read_cursor)) {
// Check if we can use a contiguous chunk
int end_size = conn->input.buf_size - conn->input.read_cursor;
if (end_size >= bytes) {
*buf = conn->input.buffer + conn->input.read_cursor;
*should_free = 0;
// Otherwise, allocate a dynamic slab, and copy
} else {
*buf = malloc(bytes);
memcpy(*buf, conn->input.buffer + conn->input.read_cursor, end_size);
memcpy(*buf + end_size, conn->input.buffer, bytes - end_size);
*should_free = 1;
}
// Handle the contiguous case
} else {
*buf = conn->input.buffer + conn->input.read_cursor;
*should_free = 0;
}
// Advance the read cursor
circbuf_advance_read(&conn->input, bytes);
return 0;
}
/**
* This method is used to peek into the input buffer without
* causing input to be consumed.
* @arg conn The client connection
* @arg bytes The number of bytes to peek
* @arg buf The output buffer to write to
* @return 0 on success, -1 if there is insufficient data.
*/
int peek_client_bytes(statsite_proxy_conn_info *conn, int bytes, char* buf) {
// Ensure we have sufficient data
if (bytes > circbuf_used_buf(&conn->input)) return -1;
// Copy the bytes
int offset = conn->input.read_cursor;
int buf_size = conn->input.buf_size;
for (int i=0; i < bytes; i++) {
buf[i] = conn->input.buffer[(offset + i) % buf_size];
}
return 0;
}
/**
* This method is used to seek the input buffer without
* consuming input. It can be used in conjunction with
* peek_client_bytes to conditionally seek.
* @arg conn The client connection
* @arg bytes The number of bytes to seek
* @return 0 on success, -1 if there is insufficient data.
*/
int seek_client_bytes(statsite_conn_info *conn, int bytes) {
if (unlikely(bytes > circbuf_used_buf(&conn->input))) return -1;
circbuf_advance_read(&conn->input, bytes);
return 0;
}
/**
* Lets the caller look at the next byte
* @arg conn The client connectoin
* @arg byte The output byte
* @return 0 on success, -1 if there is no data.
*/
int peek_client_byte(statsite_conn_info *conn, unsigned char* byte) {
if (unlikely(!circbuf_used_buf(&conn->input))) return -1;
*byte = *(unsigned char*)(conn->input.buffer+conn->input.read_cursor);
return 0;
}
/**
* This method is used to query how much data is available
* to be read from the command buffer.
* @arg conn The client connection
* @return The bytes available
*/
uint64_t available_bytes(statsite_conn_info *conn) {
// Query the circular buffer
return circbuf_used_buf(&conn->input);
}
