Save file update (incomplete)

src/duskpsp/save/savestreampsp.h

@@ -0,0 +1,77 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include <pspiofilemgr.h>
+#include <stddef.h>
+
+typedef struct {
+  SceUID fd;
+} savestreampsp_t;
+
+/**
+ * Opens a PSP save data file for reading.
+ *
+ * @param p     Stream to initialize.
+ * @param found Set to true if the file exists, false if it does not.
+ * @param slot  Save slot index.
+ * @return An error if the open fails for a reason other than missing file.
+ */
+errorret_t saveStreamOpenReadPSP(
+  savestreampsp_t *p, bool_t *found, const uint8_t slot
+);
+
+/**
+ * Opens a PSP save data file for writing, creating or truncating it.
+ * Creates the save data directory if it does not already exist.
+ *
+ * @param p    Stream to initialize.
+ * @param slot Save slot index.
+ * @return An error if the file cannot be opened for writing.
+ */
+errorret_t saveStreamOpenWritePSP(savestreampsp_t *p, const uint8_t slot);
+
+/**
+ * Closes the file descriptor held by the stream.
+ *
+ * @param p Stream to close.
+ */
+void saveStreamClosePSP(savestreampsp_t *p);
+
+/**
+ * Reads len bytes from the stream into buf.
+ *
+ * @param p   Active stream.
+ * @param buf Destination buffer.
+ * @param len Number of bytes to read.
+ * @return An error if fewer than len bytes are available.
+ */
+errorret_t saveStreamReadBytesPSP(
+  savestreampsp_t *p, void *buf, const size_t len
+);
+
+/**
+ * Writes len bytes from buf into the stream.
+ *
+ * @param p   Active stream.
+ * @param buf Source buffer.
+ * @param len Number of bytes to write.
+ * @return An error if the write fails.
+ */
+errorret_t saveStreamWriteBytesPSP(
+  savestreampsp_t *p, const void *buf, const size_t len
+);
+
+/**
+ * Seeks to an absolute byte position within the stream.
+ *
+ * @param p   Active stream.
+ * @param pos Target byte offset from the start of the file.
+ * @return An error if the seek fails.
+ */
+errorret_t saveStreamSeekPSP(savestreampsp_t *p, const size_t pos);