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authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-10-07 13:54:24 +0200
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-10-07 13:54:24 +0200
commit1fad07ce86fc2a506c59501d7fb7c7d7481525f6 (patch)
tree6ba41c514e2ddc692cb95a0fb2070dd222897c7c /lib/common/io_stdin.c
parent5597dca9c6053cd19104e18d88edb199b32e3743 (diff)
Rename libsqfshelper to libcommon
That is IMO less confusing and express what it is (i.e. what it has become) more clearly, i.e. common code shared by the utilities. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Diffstat (limited to 'lib/common/io_stdin.c')
-rw-r--r--lib/common/io_stdin.c174
1 files changed, 174 insertions, 0 deletions
diff --git a/lib/common/io_stdin.c b/lib/common/io_stdin.c
new file mode 100644
index 0000000..0e9fb17
--- /dev/null
+++ b/lib/common/io_stdin.c
@@ -0,0 +1,174 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * io_stdin.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "common.h"
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+
+
+typedef struct {
+ sqfs_file_t base;
+
+ const sparse_map_t *map;
+ sqfs_u64 offset;
+ sqfs_u64 size;
+} sqfs_file_stdin_t;
+
+
+static void stdin_destroy(sqfs_file_t *base)
+{
+ free(base);
+}
+
+static int stdin_read_at(sqfs_file_t *base, sqfs_u64 offset,
+ void *buffer, size_t size)
+{
+ sqfs_file_stdin_t *file = (sqfs_file_stdin_t *)base;
+ size_t temp_size = 0;
+ sqfs_u8 *temp = NULL;
+ sqfs_u64 diff;
+ ssize_t ret;
+
+ if (offset < file->offset)
+ return SQFS_ERROR_IO;
+
+ if (offset > file->offset) {
+ temp_size = 1024;
+ temp = alloca(temp_size);
+ }
+
+ if (offset >= file->size || (offset + size) > file->size)
+ return SQFS_ERROR_OUT_OF_BOUNDS;
+
+ while (size > 0) {
+ if (offset > file->offset) {
+ diff = file->offset - offset;
+ diff = diff > (sqfs_u64)temp_size ? temp_size : diff;
+
+ ret = read(STDIN_FILENO, temp, diff);
+ } else {
+ ret = read(STDIN_FILENO, buffer, size);
+ }
+
+ if (ret < 0) {
+ if (errno == EINTR)
+ continue;
+ return SQFS_ERROR_IO;
+ }
+
+ if (ret == 0)
+ return SQFS_ERROR_OUT_OF_BOUNDS;
+
+ if (offset <= file->offset) {
+ buffer = (char *)buffer + ret;
+ size -= ret;
+ offset += ret;
+ }
+
+ file->offset += ret;
+ }
+
+ return 0;
+}
+
+static int stdin_read_condensed(sqfs_file_t *base, sqfs_u64 offset,
+ void *buffer, size_t size)
+{
+ sqfs_file_stdin_t *file = (sqfs_file_stdin_t *)base;
+ sqfs_u64 poffset = 0, src_start;
+ size_t dst_start, diff, count;
+ const sparse_map_t *it;
+ int err;
+
+ memset(buffer, 0, size);
+
+ for (it = file->map; it != NULL; it = it->next) {
+ if (it->offset + it->count <= offset) {
+ poffset += it->count;
+ continue;
+ }
+
+ if (it->offset >= offset + size) {
+ poffset += it->count;
+ continue;
+ }
+
+ count = size;
+
+ if (offset + count >= it->offset + it->count)
+ count = it->offset + it->count - offset;
+
+ if (it->offset < offset) {
+ diff = offset - it->offset;
+
+ src_start = poffset + diff;
+ dst_start = 0;
+ count -= diff;
+ } else if (it->offset > offset) {
+ diff = it->offset - offset;
+
+ src_start = poffset;
+ dst_start = diff;
+ } else {
+ src_start = poffset;
+ dst_start = 0;
+ }
+
+ err = stdin_read_at(base, src_start,
+ (char *)buffer + dst_start, count);
+ if (err)
+ return err;
+
+ poffset += it->count;
+ }
+
+ return 0;
+}
+
+static int stdin_write_at(sqfs_file_t *base, sqfs_u64 offset,
+ const void *buffer, size_t size)
+{
+ (void)base; (void)offset; (void)buffer; (void)size;
+ return SQFS_ERROR_IO;
+}
+
+static sqfs_u64 stdin_get_size(const sqfs_file_t *base)
+{
+ return ((const sqfs_file_stdin_t *)base)->size;
+}
+
+static int stdin_truncate(sqfs_file_t *base, sqfs_u64 size)
+{
+ (void)base; (void)size;
+ return SQFS_ERROR_IO;
+}
+
+sqfs_file_t *sqfs_get_stdin_file(const sparse_map_t *map, sqfs_u64 size)
+{
+ sqfs_file_stdin_t *file = calloc(1, sizeof(*file));
+ sqfs_file_t *base = (sqfs_file_t *)file;
+
+ if (file == NULL)
+ return NULL;
+
+ file->size = size;
+ file->map = map;
+
+ base->destroy = stdin_destroy;
+ base->write_at = stdin_write_at;
+ base->get_size = stdin_get_size;
+ base->truncate = stdin_truncate;
+
+ if (map == NULL) {
+ base->read_at = stdin_read_at;
+ } else {
+ base->read_at = stdin_read_condensed;
+ }
+ return base;
+}