From 98457dcd5c0913679395a1a22442cef97212f03c Mon Sep 17 00:00:00 2001 From: Mikhail Burakov Date: Mon, 26 Dec 2022 12:14:16 +0100 Subject: Add simple growable buffer implementation --- buffer.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 buffer.c (limited to 'buffer.c') diff --git a/buffer.c b/buffer.c new file mode 100644 index 0000000..71d51f8 --- /dev/null +++ b/buffer.c @@ -0,0 +1,43 @@ +#include "buffer.h" + +#include +#include +#include +#include + +void BufferCreate(struct Buffer* buffer) { + memset(buffer, 0, sizeof(struct Buffer)); +} + +void* BufferReserve(struct Buffer* buffer, size_t size) { + size_t alloc = buffer->size + size; + if (alloc > buffer->alloc) { + void* data = realloc(buffer->data, alloc); + if (!data) return NULL; + buffer->data = data; + buffer->alloc = alloc; + } + return (char*)buffer->data + buffer->size; +} + +int BufferAppendFrom(struct Buffer* buffer, int fd) { + int nbytes; + if (ioctl(fd, FIONREAD, &nbytes) == -1) return -1; + if (!nbytes) return 0; + void* data = BufferReserve(buffer, (size_t)nbytes); + if (!data) return -1; + ssize_t result = read(fd, data, (size_t)nbytes); + if (result > 0) buffer->size += (size_t)result; + return (int)result; +} + +void BufferDiscard(struct Buffer* buffer, size_t size) { + size_t tail_size = buffer->size - size; + if (tail_size) { + const char* tail = (const char*)buffer->data + size; + memmove(buffer->data, tail, tail_size); + } + buffer->size = tail_size; +} + +void BufferDestroy(struct Buffer* buffer) { free(buffer->data); } -- cgit v1.2.3