1 files changed, 53 insertions, 0 deletions
diff --git a/src/mem/io-stream.c b/src/mem/io-stream.c
new file mode 100644
index 0000000..f7c7834
--- /dev/null
+++ b/src/mem/io-stream.c
@@ -0,0 +1,53 @@
+#include <stdio.h>
+#include "io-stream.h"
+#include "io.h"
+
+static size_t
+file_istream_read(const struct mem_io_istream *stream, void *ptr, const size_t size)
+{
+   return fread(ptr, 1, size, stream->backing);
+}
+
+struct mem_io_istream
+mem_io_istream_from_file(FILE *file)
+{
+   return (struct mem_io_istream){
+      .read = file_istream_read,
+      .backing = file
+   };
+}
+
+size_t
+mem_io_write_from_stream(const struct mem_io *io, const struct mem_io_istream *stream, const size_t offset, const size_t size)
+{
+   size_t trw = 0;
+   unsigned char buf[4096];
+   for (size_t rd, trd = 0; (rd = stream->read(stream, buf, (trd + sizeof(buf) > size ? size - trd : sizeof(buf)))) && trd < size; trd += rd)
+      trw += io->write(io, buf, offset + trd, rd);
+   return trw;
+}
+
+static size_t
+file_ostream_write(const struct mem_io_ostream *stream, const void *ptr, const size_t size)
+{
+   return fwrite(ptr, 1, size, stream->backing);
+}
+
+struct mem_io_ostream
+mem_io_ostream_from_file(FILE *file)
+{
+   return (struct mem_io_ostream){
+      .write = file_ostream_write,
+      .backing = file
+   };
+}
+
+size_t
+mem_io_read_to_stream(const struct mem_io *io, const struct mem_io_ostream *stream, const size_t offset, const size_t size)
+{
+   size_t trw = 0;
+   unsigned char buf[4096];
+   for (size_t rd, trd = 0; (rd = io->read(io, buf, offset + trd, (trd + sizeof(buf) > size ? size - trd : sizeof(buf)))) && trd < size; trd += rd)
+      trw += stream->write(stream, buf, rd);
+   return trw;
+}