stream.c

#include "config.h"
#include "debug.h"
#include <clod/stream.h>
 
int clod_stream_copy(clod_stream *dst, clod_stream *src, void *const buffer, const size_t buffer_size, size_t *total_transferred) {
    if (buffer_size == 0) {
        debug(CLOD_DEBUG, "Invalid buffer size for stream copy.");
        return CLOD_STREAM_INVALID;
    }
 
    if (dst->write == nullptr) {
        debug(CLOD_DEBUG, "Provided stream %ptr doesn't support writing.", (void*)dst);
        return CLOD_STREAM_INVALID;
    }
 
    if (src->read == nullptr) {
        debug(CLOD_DEBUG, "Provided stream %ptr doesn't support reading.", (void*)src);
         return CLOD_STREAM_INVALID;
    }
 
    size_t transferred = 0;
    while (1) {
        struct clod_string buff = (struct clod_string){ .ptr = buffer, .len = 0, .cap = (ptrdiff_t)buffer_size};
        int read_res = src->read(src, &buff);
 
        int write_res = 0;
        if (buff.len > 0) {
            write_res = dst->write(dst, &buff);
            transferred += (size_t)buff.ptr - (size_t)buffer;
        }
        
        if (buff.len > 0) {
            debug(CLOD_DEBUG, "Short write to stream %ptr.", (void*)dst);
        }
 
        if (read_res == CLOD_STREAM_EOF) {
            if (total_transferred) *total_transferred = transferred;
            return 0;
        }
 
        if (read_res != CLOD_STREAM_OK) {
            if (total_transferred) *total_transferred = transferred;
            return read_res;
        }
        if (write_res != CLOD_STREAM_OK) {
            if (total_transferred) *total_transferred = transferred;
            return write_res;
        }
    }
}