1 files changed, 135 insertions, 0 deletions
diff --git a/lib/common/src/stream.c b/lib/common/src/stream.c
new file mode 100644
index 0000000..a557360
--- /dev/null
+++ b/lib/common/src/stream.c
@@ -0,0 +1,135 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * mem.c
+ *
+ * Copyright (C) 2023 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+#include "compat.h"
+#include "common.h"
+#include "sqfs/io.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#if defined(_WIN32) || defined(__WINDOWS__)
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#else
+#include <unistd.h>
+#define STD_INPUT_HANDLE STDIN_FILENO
+#define STD_OUTPUT_HANDLE STDOUT_FILENO
+#define GetStdHandle(hnd) hnd
+#endif
+
+typedef struct {
+	sqfs_istream_t base;
+
+	sqfs_u8 *buffer;
+	size_t bufsz;
+
+	const void *data;
+	size_t size;
+	size_t offset;
+	size_t visible;
+
+	char *name;
+} mem_istream_t;
+
+static int mem_get_buffered_data(sqfs_istream_t *strm, const sqfs_u8 **out,
+				 size_t *size, size_t want)
+{
+	mem_istream_t *mem = (mem_istream_t *)strm;
+	size_t have = mem->size - mem->offset;
+
+	if (have > mem->bufsz)
+		have = mem->bufsz;
+
+	if (want > have)
+		want = have;
+
+	if (mem->visible == 0 || mem->visible < want) {
+		memcpy(mem->buffer + mem->visible,
+		       (const char *)mem->data + mem->offset + mem->visible,
+		       have - mem->visible);
+		mem->visible = have;
+	}
+
+	*out = mem->buffer;
+	*size = mem->visible;
+	return (mem->visible == 0) ? 1 : 0;
+}
+
+static void mem_advance_buffer(sqfs_istream_t *strm, size_t count)
+{
+	mem_istream_t *mem = (mem_istream_t *)strm;
+
+	assert(count <= mem->visible);
+
+	if (count > 0 && count < mem->visible)
+		memmove(mem->buffer, mem->buffer + count, mem->visible - count);
+
+	mem->offset += count;
+	mem->visible -= count;
+
+	if (mem->visible < mem->bufsz) {
+		memset(mem->buffer + mem->visible, 0,
+		       mem->bufsz - mem->visible);
+	}
+}
+
+static const char *mem_in_get_filename(sqfs_istream_t *strm)
+{
+	return ((mem_istream_t *)strm)->name;
+}
+
+static void mem_in_destroy(sqfs_object_t *obj)
+{
+	free(((mem_istream_t *)obj)->buffer);
+	free(((mem_istream_t *)obj)->name);
+	free(obj);
+}
+
+sqfs_istream_t *istream_memory_create(const char *name, size_t bufsz,
+				      const void *data, size_t size)
+{
+	mem_istream_t *mem = calloc(1, sizeof(*mem));
+	sqfs_istream_t *strm = (sqfs_istream_t *)mem;
+
+	if (mem == NULL)
+		return NULL;
+
+	sqfs_object_init(mem, mem_in_destroy, NULL);
+
+	mem->name = strdup(name);
+	if (mem->name == NULL)
+		return sqfs_drop(mem);
+
+	mem->buffer = malloc(bufsz);
+	if (mem->buffer == NULL)
+		return sqfs_drop(mem);
+
+	mem->data = data;
+	mem->size = size;
+	mem->bufsz = bufsz;
+	strm->get_buffered_data = mem_get_buffered_data;
+	strm->advance_buffer = mem_advance_buffer;
+	strm->get_filename = mem_in_get_filename;
+	return strm;
+}
+
+int istream_open_stdin(sqfs_istream_t **out)
+{
+	sqfs_file_handle_t hnd = GetStdHandle(STD_INPUT_HANDLE);
+
+	return sqfs_istream_open_handle(out, "stdin", hnd, 0);
+}
+
+int ostream_open_stdout(sqfs_ostream_t **out)
+{
+	sqfs_file_handle_t hnd = GetStdHandle(STD_OUTPUT_HANDLE);
+
+	return sqfs_ostream_open_handle(out, "stdout", hnd,
+					SQFS_FILE_OPEN_NO_SPARSE);
+}