From 484cd01590ec488cca1f8a5c7c76cd223609e299 Mon Sep 17 00:00:00 2001
From: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Date: Thu, 15 Jun 2023 15:16:03 +0200
Subject: Migrate file istream/ostream from libio to libsquashfs

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
---
 include/sqfs/io.h | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

(limited to 'include/sqfs/io.h')

diff --git a/include/sqfs/io.h b/include/sqfs/io.h
index 1138fc0..eaf74a6 100644
--- a/include/sqfs/io.h
+++ b/include/sqfs/io.h
@@ -329,6 +329,80 @@ SQFS_API int sqfs_open_native_file(sqfs_file_handle_t *out,
  */
 SQFS_API sqfs_file_t *sqfs_open_file(const char *filename, sqfs_u32 flags);
 
+/**
+ * @brief Create an input stream for an OS native file handle.
+ *
+ * @memberof sqfs_istream_t
+ *
+ * The functions takes up ownership of the file handle and takes care
+ * of cleaning it up. On failure, the handle remains usable, and ownership
+ * remains with the caller.
+ *
+ * @param out Returns a pointer to an input stream on success.
+ * @param path The name to associate with the handle.
+ * @param fd A native file handle.
+ *
+ * @return Zero on success, a negative @ref SQFS_ERROR number on failure
+ */
+SQFS_API
+int sqfs_istream_open_handle(sqfs_istream_t **out, const char *path,
+			     sqfs_file_handle_t fd);
+
+/**
+ * @brief Create an output stream that writes to an OS native file handle.
+ *
+ * @memberof sqfs_ostream_t
+ *
+ * If the flag SQFS_FILE_OPEN_NO_SPARSE is set, the underlying implementation
+ * always writes chunks of zero bytes when passing a NULL pointer to append.
+ * Otherwise, it tries to use seek/truncate style APIs to create sparse output
+ * files.
+ *
+ * @param out Returns a pointer to an output stream on success.
+ * @param path The name to associate with the handle.
+ * @param fd A native file handle.
+ * @param flags A combination of flags.
+ *
+ * @return Zero on success, a negative @ref SQFS_ERROR number on failure
+ */
+SQFS_API int sqfs_ostream_open_handle(sqfs_ostream_t **out, const char *path,
+				      sqfs_file_handle_t hnd, int flags);
+
+/**
+ * @brief Create an input stream that reads from a file.
+ *
+ * @memberof sqfs_istream_t
+ *
+ * @param out Returns a pointer to an input stream on success.
+ * @param path A path to the file to open or create.
+ *
+ * @return Zero on success, a negative @ref SQFS_ERROR number on failure
+ */
+SQFS_API int sqfs_istream_open_file(sqfs_istream_t **out, const char *path);
+
+/**
+ * @brief Create an output stream that writes to a file.
+ *
+ * @memberof sqfs_ostream_t
+ *
+ * If the file does not yet exist, it is created. If it does exist this
+ * function fails, unless the flag SQFS_FILE_OPEN_OVERWRITE is set, in which
+ * case the file is opened and its contents are discarded.
+ *
+ * If the flag SQFS_FILE_OPEN_NO_SPARSE is set, the underlying implementation
+ * always writes chunks of zero bytes when passing a NULL pointer to append.
+ * Otherwise, it tries to use seek/truncate style APIs to create sparse output
+ * files.
+ *
+ * @param out Returns a pointer to an output stream on success.
+ * @param path A path to the file to open or create.
+ * @param flags A combination of flags controling how to open/create the file.
+ *
+ * @return Zero on success, a negative @ref SQFS_ERROR number on failure
+ */
+SQFS_API int sqfs_ostream_open_file(sqfs_ostream_t **out,
+				    const char *path, int flags);
+
 /**
  * @brief Read data from an input stream
  *
-- 
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