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- /** @file buf.c
- * @brief Dynamic buffer.
- *
- */
- #include <stdlib.h>
- #include <stdint.h>
- #include <stdio.h>
- #include <string.h>
- #include <assert.h>
- #include "faux/faux.h"
- #include "faux/str.h"
- #include "faux/buf.h"
- #define DATA_CHUNK 4096
- struct faux_buf_s {
- size_t limit;
- faux_list_t *list;
- size_t rpos;
- size_t wpos;
- size_t size;
- };
- /** @brief Create new buf I/O object.
- *
- * Constructor gets associated file descriptor to operate on it. File
- * descriptor must be nonblocked. If not so then constructor will set
- * nonblock flag itself.
- *
- * @param [in] fd File descriptor.
- * @return Allocated object or NULL on error.
- */
- faux_buf_t *faux_buf_new(void)
- {
- faux_buf_t *buf = NULL;
- buf = faux_zmalloc(sizeof(*buf));
- assert(buf);
- if (!buf)
- return NULL;
- // Init
- buf->limit = FAUX_BUF_UNLIMITED;
- buf->list = faux_list_new(FAUX_LIST_UNSORTED, FAUX_LIST_NONUNIQUE,
- NULL, NULL, faux_free);
- buf->rpos = 0;
- buf->wpos = 0;
- buf->size = 0;
- return buf;
- }
- /** @brief Free buf I/O object.
- *
- * @param [in] buf I/O object.
- */
- void faux_buf_free(faux_buf_t *buf)
- {
- if (!buf)
- return;
- faux_list_free(buf->list);
- faux_free(buf);
- }
- ssize_t faux_buf_limit(const faux_buf_t *buf)
- {
- assert(buf);
- if (!buf)
- return -1;
- return buf->limit;
- }
- /** @brief Set size limit.
- *
- * Read limits define conditions when the read callback will be executed.
- * Buffer must contain data amount greater or equal to "min" value. Callback
- * will not get data amount greater than "max" value. If min == max then
- * callback will be executed with fixed data size. The "max" value can be "0".
- * It means indefinite i.e. data transferred to callback can be really large.
- *
- * @param [in] buf Allocated and initialized buf I/O object.
- * @param [in] min Minimal data amount.
- * @param [in] max Maximal data amount. The "0" means indefinite.
- * @return BOOL_TRUE - success, BOOL_FALSE - error.
- */
- bool_t faux_buf_set_limit(faux_buf_t *buf, size_t limit)
- {
- assert(buf);
- if (!buf)
- return BOOL_FALSE;
- buf->limit = limit;
- return BOOL_TRUE;
- }
- #if 0
- /** @brief Get amount of unused space within current data chunk.
- *
- * Inernal static function.
- *
- * @param [in] list Internal buffer (list of chunks) to inspect.
- * @param [in] pos Current write position within last chunk
- * @return Size of unused space or < 0 on error.
- */
- static ssize_t free_space(faux_list_t *list, size_t pos)
- {
- if (!list)
- return -1;
- if (faux_list_len(list) == 0)
- return 0;
- return (DATA_CHUNK - pos);
- }
- /** @brief buf data write.
- *
- * All given data will be stored to internal buffer (list of data chunks).
- * Then function will try to write stored data to file descriptor in
- * non-blocking mode. Note some data can be left within buffer. In this case
- * the "stall" callback will be executed to inform about it. To try to write
- * the rest of the data user can be call faux_buf_out() function. Both
- * functions will not block.
- *
- * @param [in] buf Allocated and initialized buf I/O object.
- * @param [in] data Data buffer to write.
- * @param [in] len Data length to write.
- * @return Length of stored/writed data or < 0 on error.
- */
- ssize_t faux_buf_write(faux_buf_t *buf, void *data, size_t len)
- {
- void *new_chunk = NULL;
- size_t data_left = len;
- assert(buf);
- if (!buf)
- return -1;
- assert(data);
- if (!data)
- return -1;
- while (data_left != 0) {
- ssize_t bytes_free = 0;
- size_t copy_len = 0;
- char *chunk_ptr = NULL;
- // Allocate new chunk if necessary
- bytes_free = free_space(buf->o_list, buf->o_wpos);
- if (bytes_free < 0)
- return -1;
- if (0 == bytes_free) {
- new_chunk = faux_malloc(DATA_CHUNK);
- assert(new_chunk);
- faux_list_add(buf->o_list, new_chunk);
- buf->o_wpos = 0;
- bytes_free = free_space(buf->o_list, buf->o_wpos);
- }
- // Copy data
- chunk_ptr = faux_list_data(faux_list_tail(buf->o_list));
- copy_len = (data_left < (size_t)bytes_free) ? data_left : (size_t)bytes_free;
- memcpy(chunk_ptr + buf->o_wpos, data + len - data_left,
- copy_len);
- buf->o_wpos += copy_len;
- data_left -= copy_len;
- buf->o_size += copy_len;
- if (buf->o_size >= buf->o_overflow)
- return -1;
- }
- // Try to real write data to fd in nonblocked mode
- faux_buf_out(buf);
- return len;
- }
- /** @brief Get amount of available data within first chunk.
- *
- * Inernal static function.
- *
- * @param [in] list Internal buffer (list of chunks) to inspect.
- * @param [in] rpos Current read position within chunk.
- * @param [in] wpos Current write position within chunk.
- * @return Available data length or < 0 on error.
- */
- static ssize_t data_avail(faux_list_t *list, size_t rpos, size_t wpos)
- {
- size_t len = 0;
- if (!list)
- return -1;
- len = faux_list_len(list);
- if (len == 0)
- return 0;
- if (len > 1)
- return (DATA_CHUNK - rpos);
- // Single chunk
- return (wpos - rpos);
- }
- /** @brief Write output buffer to fd in non-blocking mode.
- *
- * Previously data must be written to internal buffer by faux_buf_write()
- * function. But some data can be left within internal buffer because can't be
- * written to fd in non-blocking mode. This function tries to write the rest of
- * data to fd in non-blocking mode. So function doesn't block. It can be called
- * after select() or poll() if fd is ready to be written to. If function can't
- * to write all buffer to fd it executes "stall" callback to inform about it.
- *
- * @param [in] buf Allocated and initialized buf I/O object.
- * @return Length of data actually written or < 0 on error.
- */
- ssize_t faux_buf_out(faux_buf_t *buf)
- {
- ssize_t total_written = 0;
- assert(buf);
- if (!buf)
- return -1;
- while (buf->o_size > 0) {
- faux_list_node_t *node = NULL;
- char *chunk_ptr = NULL;
- ssize_t data_to_write = 0;
- ssize_t bytes_written = 0;
- bool_t postpone = BOOL_FALSE;
- node = faux_list_head(buf->o_list);
- if (!node) // List is empty while o_size > 0
- return -1;
- chunk_ptr = faux_list_data(node);
- data_to_write = data_avail(buf->o_list,
- buf->o_rpos, buf->o_wpos);
- if (data_to_write <= 0) // Strange case
- return -1;
- bytes_written = write(buf->fd, chunk_ptr + buf->o_rpos,
- data_to_write);
- if (bytes_written > 0) {
- buf->o_size -= bytes_written;
- total_written += bytes_written;
- }
- if (bytes_written < 0) {
- if ( // Something went wrong
- (errno != EINTR) &&
- (errno != EAGAIN) &&
- (errno != EWOULDBLOCK)
- )
- return -1;
- // Postpone next read
- postpone = BOOL_TRUE;
- // Not whole data block was written
- } else if (bytes_written != data_to_write) {
- buf->o_rpos += bytes_written;
- // Postpone next read
- postpone = BOOL_TRUE;
- }
- // Postponed
- if (postpone) {
- // Execute callback
- if (buf->stall_cb)
- buf->stall_cb(buf, buf->o_size,
- buf->stall_udata);
- break;
- }
- // Not postponed. Current chunk was fully written. So
- // remove it from list.
- buf->o_rpos = 0;
- faux_list_del(buf->o_list, node);
- }
- return total_written;
- }
- /** @brief Read data and store it to internal buffer in non-blocking mode.
- *
- * Reads fd and puts data to internal buffer. It can't be blocked. If length of
- * data stored within internal buffer is greater or equal than "min" limit then
- * function will execute "read" callback. It allocates linear buffer, copies
- * data to it and give it to callback. Note this function will never free
- * allocated buffer. So callback must do it or it must be done later. Function
- * will not allocate buffer larger than "max" read limit. If "max" limit is "0"
- * (it means indefinite) then function will pass all available data to callback.
- *
- * @param [in] buf Allocated and initialized buf I/O object.
- * @return Length of data actually readed or < 0 on error.
- */
- ssize_t faux_buf_in(faux_buf_t *buf)
- {
- void *new_chunk = NULL;
- ssize_t total_readed = 0;
- ssize_t bytes_readed = 0;
- ssize_t bytes_free = 0; // Free space within current (last) chunk
- assert(buf);
- if (!buf)
- return -1;
- do {
- char *chunk_ptr = NULL;
- // Allocate new chunk if necessary
- bytes_free = free_space(buf->i_list, buf->i_wpos);
- if (bytes_free < 0)
- return -1;
- if (0 == bytes_free) { // We need to allocate additional chunk
- new_chunk = faux_malloc(DATA_CHUNK);
- assert(new_chunk);
- faux_list_add(buf->i_list, new_chunk);
- buf->i_wpos = 0;
- bytes_free = free_space(buf->i_list, buf->i_wpos);
- }
- // Read data to last chunk
- chunk_ptr = faux_list_data(faux_list_tail(buf->i_list));
- bytes_readed = read(buf->fd, chunk_ptr + buf->i_wpos, bytes_free);
- if (bytes_readed < 0) {
- if ( // Something went wrong
- (errno != EINTR) &&
- (errno != EAGAIN) &&
- (errno != EWOULDBLOCK)
- )
- return -1;
- }
- if (bytes_readed > 0) {
- buf->i_wpos += bytes_readed;
- buf->i_size += bytes_readed;
- total_readed += bytes_readed;
- }
- if (buf->i_size >= buf->i_overflow)
- return -1;
- // Check for amount of stored data
- while (buf->i_size >= buf->min) {
- size_t copy_len = 0;
- size_t full_size = 0;
- char *buf = NULL;
- char *buf_ptr = NULL;
- if (FAUX_buf_UNLIMITED == buf->max) { // Indefinite
- copy_len = buf->i_size; // Take all data
- } else {
- copy_len = (buf->i_size < buf->max) ?
- buf->i_size : buf->max;
- }
- full_size = copy_len; // Save full length value
- buf = faux_malloc(full_size);
- buf_ptr = buf;
- while (copy_len > 0) {
- size_t data_to_write = 0;
- faux_list_node_t *node = faux_list_head(buf->i_list);
- char *chunk_ptr = NULL;
- if (!node) // Something went wrong
- return -1;
- chunk_ptr = faux_list_data(node);
- data_to_write = data_avail(buf->i_list,
- buf->i_rpos, buf->i_wpos);
- if (copy_len < data_to_write)
- data_to_write = copy_len;
- memcpy(buf_ptr, chunk_ptr + buf->i_rpos,
- data_to_write);
- copy_len -= data_to_write;
- buf->i_size -= data_to_write;
- buf->i_rpos += data_to_write;
- buf_ptr += data_to_write;
- if (data_avail(buf->i_list,
- buf->i_rpos, buf->i_wpos) <= 0) {
- buf->i_rpos = 0;
- faux_list_del(buf->i_list, node);
- }
- }
- // Execute callback
- if (buf->read_cb)
- buf->read_cb(buf, buf,
- full_size, buf->read_udata);
- }
- } while (bytes_readed == bytes_free);
- return total_readed;
- }
- #endif
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