diff options
Diffstat (limited to 'src/buffer.h')
| -rw-r--r-- | src/buffer.h | 30 |
1 files changed, 26 insertions, 4 deletions
diff --git a/src/buffer.h b/src/buffer.h index 489e509..ac1df3d 100644 --- a/src/buffer.h +++ b/src/buffer.h @@ -23,21 +23,36 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ +/** + \file buffer.h + + Buffer management +*/ + #pragma once #include "log.h" +/** A buffer descriptor */ struct fastd_buffer { - void *base; - size_t base_len; + void *base; /**< The beginning of the allocated memory area */ + size_t base_len; /**< The size of the allocated memory area */ - void *data; - size_t len; + void *data; /**< The beginning of the actual data in the buffer */ + size_t len; /**< The data length */ }; +/** + Allocate a new buffer + + A buffer can have head and tail space which allows changing with data size without moving the data. + + The buffer is always allocated aligned to 16 bytes to allow efficient access for SIMD instructions + etc. in crypto implementations +*/ static inline fastd_buffer_t fastd_buffer_alloc(const size_t len, size_t head_space, size_t tail_space) { size_t base_len = head_space+len+tail_space; void *ptr; @@ -48,17 +63,20 @@ static inline fastd_buffer_t fastd_buffer_alloc(const size_t len, size_t head_sp return (fastd_buffer_t){ .base = ptr, .base_len = base_len, .data = ptr+head_space, .len = len }; } +/** Duplicates a buffer */ static inline fastd_buffer_t fastd_buffer_dup(const fastd_buffer_t buffer, size_t head_space, size_t tail_space) { fastd_buffer_t new_buffer = fastd_buffer_alloc(buffer.len, head_space, tail_space); memcpy(new_buffer.data, buffer.data, buffer.len); return new_buffer; } +/** Frees a buffer */ static inline void fastd_buffer_free(fastd_buffer_t buffer) { free(buffer.base); } +/** Pulls the data head (decreases the head space) */ static inline void fastd_buffer_pull_head(fastd_buffer_t *buffer, size_t len) { if (len > (size_t)(buffer->data - buffer->base)) exit_bug("tried to pull buffer across base"); @@ -67,17 +85,20 @@ static inline void fastd_buffer_pull_head(fastd_buffer_t *buffer, size_t len) { buffer->len += len; } +/** Pulls the data head and fills with zeroes */ static inline void fastd_buffer_pull_head_zero(fastd_buffer_t *buffer, size_t len) { fastd_buffer_pull_head(buffer, len); memset(buffer->data, 0, len); } +/** Pulls the data head and copies data into the new space */ static inline void fastd_buffer_pull_head_from(fastd_buffer_t *buffer, const void *data, size_t len) { fastd_buffer_pull_head(buffer, len); memcpy(buffer->data, data, len); } +/** Pushes the buffer head (increases the head space) */ static inline void fastd_buffer_push_head(fastd_buffer_t *buffer, size_t len) { if (buffer->len < len) exit_bug("tried to push buffer across tail"); @@ -86,6 +107,7 @@ static inline void fastd_buffer_push_head(fastd_buffer_t *buffer, size_t len) { buffer->len -= len; } +/** Pushes the buffer head, copying the removed buffer data somewhere else */ static inline void fastd_buffer_push_head_to(fastd_buffer_t *buffer, void *data, size_t len) { memcpy(data, buffer->data, len); fastd_buffer_push_head(buffer, len); |