Save file update (incomplete)

src/dusklinux/CMakeLists.txt

@@ -14,5 +14,6 @@ add_subdirectory(asset)
 add_subdirectory(log)
 add_subdirectory(input)
 add_subdirectory(network)
+add_subdirectory(save)
 add_subdirectory(system)
 add_subdirectory(time)

src/dusklinux/save/CMakeLists.txt

@@ -0,0 +1,11 @@
+# Copyright (c) 2026 Dominic Masters
+#
+# This software is released under the MIT License.
+# https://opensource.org/licenses/MIT
+
+# Sources
+target_sources(${DUSK_LIBRARY_TARGET_NAME}
+  PUBLIC
+    savelinux.c
+    savestreamlinux.c
+)

src/dusklinux/save/savelinux.c

@@ -0,0 +1,84 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "save/save.h"
+#include "util/string.h"
+#include <stdio.h>
+#include <sys/stat.h>
+#include <errno.h>
+
+errorret_t saveInitLinux(void) {
+  stringCopy(SAVE.platform.savePath, SAVE_LINUX_PATH, SAVE_LINUX_PATH_MAX);
+
+  if(mkdir(SAVE.platform.savePath, 0755) != 0 && errno != EEXIST) {
+    errorThrow("Failed to create save directory: %s", SAVE.platform.savePath);
+  }
+
+  errorOk();
+}
+
+errorret_t saveDisposeLinux(void) {
+  errorOk();
+}
+
+errorret_t saveLoadLinux(const uint8_t slot, savefile_t *file) {
+  char_t path[SAVE_LINUX_PATH_MAX];
+  snprintf(path, SAVE_LINUX_PATH_MAX, SAVE_LINUX_FILE_FORMAT,
+    SAVE.platform.savePath, (uint32_t)slot
+  );
+
+  FILE *f = fopen(path, "rb");
+  if(!f) {
+    file->exists = false;
+    errorOk();
+  }
+
+  size_t read = fread(file, sizeof(savefile_t), 1, f);
+  fclose(f);
+
+  if(read != 1) {
+    file->exists = false;
+    errorThrow("Failed to read save data for slot %u", (uint32_t)slot);
+  }
+
+  file->exists = true;
+  errorOk();
+}
+
+errorret_t saveWriteLinux(const uint8_t slot, const savefile_t *file) {
+  char_t path[SAVE_LINUX_PATH_MAX];
+  snprintf(path, SAVE_LINUX_PATH_MAX, SAVE_LINUX_FILE_FORMAT,
+    SAVE.platform.savePath, (uint32_t)slot
+  );
+
+  FILE *f = fopen(path, "wb");
+  if(!f) {
+    errorThrow("Failed to open save file for writing: slot %u", (uint32_t)slot);
+  }
+
+  size_t written = fwrite(file, sizeof(savefile_t), 1, f);
+  fclose(f);
+
+  if(written != 1) {
+    errorThrow("Failed to write save data for slot %u", (uint32_t)slot);
+  }
+
+  errorOk();
+}
+
+errorret_t saveDeleteLinux(const uint8_t slot) {
+  char_t path[SAVE_LINUX_PATH_MAX];
+  snprintf(path, SAVE_LINUX_PATH_MAX, SAVE_LINUX_FILE_FORMAT,
+    SAVE.platform.savePath, (uint32_t)slot
+  );
+
+  if(remove(path) != 0 && errno != ENOENT) {
+    errorThrow("Failed to delete save file for slot %u", (uint32_t)slot);
+  }
+
+  errorOk();
+}

src/dusklinux/save/savelinux.h

@@ -0,0 +1,61 @@
+/**
+ * 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 "save/savefile.h"
+
+#define SAVE_LINUX_PATH_MAX FILENAME_MAX
+#define SAVE_LINUX_FILE_FORMAT "%s/save_%u.dat"
+
+#ifndef SAVE_LINUX_PATH
+  #define SAVE_LINUX_PATH "./saves"
+#endif
+
+typedef struct {
+  char_t savePath[SAVE_LINUX_PATH_MAX];
+} savelinux_t;
+
+/**
+ * Initializes the save system on Linux.
+ *
+ * @return An error code if initialization fails.
+ */
+errorret_t saveInitLinux(void);
+
+/**
+ * Disposes of the save system on Linux.
+ *
+ * @return An error code if disposal fails.
+ */
+errorret_t saveDisposeLinux(void);
+
+/**
+ * Loads a save file from disk for the given slot.
+ *
+ * @param slot The save slot index.
+ * @param file Output save file data.
+ * @return An error code if the load fails.
+ */
+errorret_t saveLoadLinux(const uint8_t slot, savefile_t *file);
+
+/**
+ * Writes a save file to disk for the given slot.
+ *
+ * @param slot The save slot index.
+ * @param file Save file data to write.
+ * @return An error code if the write fails.
+ */
+errorret_t saveWriteLinux(const uint8_t slot, const savefile_t *file);
+
+/**
+ * Deletes the save file for the given slot from disk.
+ *
+ * @param slot The save slot index.
+ * @return An error code if the delete fails.
+ */
+errorret_t saveDeleteLinux(const uint8_t slot);

src/dusklinux/save/saveplatform.h

@@ -0,0 +1,30 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "save/savelinux.h"
+#include "save/savestreamlinux.h"
+
+typedef savelinux_t saveplatform_t;
+typedef savestreamlinux_t saveplatformstream_t;
+
+#define saveInitPlatform saveInitLinux
+#define saveDisposePlatform saveDisposeLinux
+#define saveDeletePlatform saveDeleteLinux
+
+#define saveStreamOpenReadPlatform(stream, slot) \
+  saveStreamOpenReadLinux(&(stream)->platform, &(stream)->found, slot)
+#define saveStreamOpenWritePlatform(stream, slot) \
+  saveStreamOpenWriteLinux(&(stream)->platform, slot)
+#define saveStreamClosePlatform(stream) \
+  saveStreamCloseLinux(&(stream)->platform)
+#define saveStreamReadBytesPlatform(stream, buf, len) \
+  saveStreamReadBytesLinux(&(stream)->platform, buf, len)
+#define saveStreamWriteBytesPlatform(stream, buf, len) \
+  saveStreamWriteBytesLinux(&(stream)->platform, buf, len)
+#define saveStreamSeekPlatform(stream, pos) \
+  saveStreamSeekLinux(&(stream)->platform, pos)

src/dusklinux/save/savestreamlinux.c

@@ -0,0 +1,75 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "save/save.h"
+#include "save/savestreamlinux.h"
+#include "util/string.h"
+#include <sys/stat.h>
+#include <errno.h>
+
+static void _saveStreamGetPath(
+  char_t *out, const size_t max, const uint8_t slot
+) {
+  snprintf(
+    out, max, SAVE_LINUX_FILE_FORMAT,
+    SAVE.platform.savePath, (uint32_t)slot
+  );
+}
+
+errorret_t saveStreamOpenReadLinux(
+  savestreamlinux_t *p, bool_t *found, const uint8_t slot
+) {
+  char_t path[SAVE_LINUX_PATH_MAX];
+  _saveStreamGetPath(path, SAVE_LINUX_PATH_MAX, slot);
+
+  p->file = fopen(path, "rb");
+  *found = (p->file != NULL);
+  errorOk();
+}
+
+errorret_t saveStreamOpenWriteLinux(savestreamlinux_t *p, const uint8_t slot) {
+  char_t path[SAVE_LINUX_PATH_MAX];
+  _saveStreamGetPath(path, SAVE_LINUX_PATH_MAX, slot);
+
+  p->file = fopen(path, "wb");
+  if(!p->file) {
+    errorThrow("Failed to open save file for writing: slot %u", (uint32_t)slot);
+  }
+  errorOk();
+}
+
+void saveStreamCloseLinux(savestreamlinux_t *p) {
+  if(p->file) {
+    fclose(p->file);
+    p->file = NULL;
+  }
+}
+
+errorret_t saveStreamReadBytesLinux(
+  savestreamlinux_t *p, void *buf, const size_t len
+) {
+  if(fread(buf, 1, len, p->file) != len) {
+    errorThrow("Unexpected end of save file");
+  }
+  errorOk();
+}
+
+errorret_t saveStreamWriteBytesLinux(
+  savestreamlinux_t *p, const void *buf, const size_t len
+) {
+  if(fwrite(buf, 1, len, p->file) != len) {
+    errorThrow("Failed to write save data");
+  }
+  errorOk();
+}
+
+errorret_t saveStreamSeekLinux(savestreamlinux_t *p, const size_t pos) {
+  if(fseek(p->file, (long)pos, SEEK_SET) != 0) {
+    errorThrow("Failed to seek in save file");
+  }
+  errorOk();
+}

src/dusklinux/save/savestreamlinux.h

@@ -0,0 +1,78 @@
+/**
+ * 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 <stdio.h>
+#include <stddef.h>
+
+typedef struct {
+  FILE *file;
+} savestreamlinux_t;
+
+/**
+ * Opens a save slot 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 saveStreamOpenReadLinux(
+  savestreamlinux_t *p, bool_t *found, const uint8_t slot
+);
+
+/**
+ * Opens a save slot file for writing, creating or truncating it.
+ *
+ * @param p    Stream to initialize.
+ * @param slot Save slot index.
+ * @return An error if the file cannot be opened for writing.
+ */
+errorret_t saveStreamOpenWriteLinux(
+  savestreamlinux_t *p, const uint8_t slot
+);
+
+/**
+ * Closes the file handle held by the stream.
+ *
+ * @param p Stream to close.
+ */
+void saveStreamCloseLinux(savestreamlinux_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 saveStreamReadBytesLinux(
+  savestreamlinux_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 saveStreamWriteBytesLinux(
+  savestreamlinux_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 saveStreamSeekLinux(savestreamlinux_t *p, const size_t pos);