1 files changed, 79 insertions, 32 deletions

diff --git a/arm9/source/types/pathbuf.c b/arm9/source/types/pathbuf.c
index 1a610c8..e94b955 100644
--- a/arm9/source/types/pathbuf.c
+++ b/arm9/source/types/pathbuf.c
@@ -1,52 +1,99 @@
-#include <nds.h>
 #include "pathbuf.h"
 
-u8 pb_read(PathBuf *buf) {
+
+// Read the next byte of the path buffer, or zero if all bytes have been read.
+u8 pathbuf_read(PathBuf *buf) {
     u8 output = buf->mem[buf->p];
     if (output) buf->p++;
     return output;
 }
 
-void pb_clear(PathBuf *buf) {
-    memset(&buf->mem, 0, 256);
+// Clear a path buffer.
+void pathbuf_clear(PathBuf *buf) {
+    for (int i=0; i<256; i++) buf->mem[i] = 0;
+    buf->p = 0;
 }
 
-void pb_reset(PathBuf *buf, bool to_name) {
+// Move the pointer to either the start of the path buffer or to the start of
+// the final path component.
+void pathbuf_set_pointer(PathBuf *buf, bool to_final_component) {
     buf->p = 0;
-    if (to_name) for (int i=0; i<255; i++) {
-        if (buf->mem[i] == '/') {
-            buf->p = i+1;
-        } else if (buf->mem[i] == 0) {
-            break;
+    if (to_final_component) {
+        for (int i=0; i<255; i++) {
+            if (buf->mem[i] == '/') {
+                buf->p = i+1;
+            } else if (buf->mem[i] == 0) {
+                break;
+            }
         }
     }
 }
 
-// Push a byte to a PathBuf, return true and reset the pointer if byte is null.
-bool pb_push_byte(PathBuf *buf, u8 byte) {
-    // Stop before overwriting the pointer.
-    if (buf->p != 0xff) {
-        buf->mem[buf->p++] = byte;
-    }
-    if (byte == 0) {
-        buf->p = 0;
-        return true;
-    } else {
-        return false;
-    }
+// Populate a path buffer with a bytestring.
+void pathbuf_populate(PathBuf *buf, u8 *path) {
+    pathbuf_clear(buf);
+    u8 c;
+    for (int i=0; i<256; i++) {
+        c = path[i];
+        buf->mem[i] = c;
+        if (c == 0) return;
+    };
 }
 
-bool pb_is_terminated(PathBuf *buf) {
-    for (int i=0; i<255; i++) {
-        if (buf->mem[i] == 0) {
-            return true;
-        }
-    }
-    return false;
+// Push a byte to a path buffer, return true and reset pointer if byte is null.
+bool pathbuf_push(PathBuf *buf, u8 byte) {
+    buf->mem[buf->p++] = byte;
+    return byte == 0;
 }
 
-void pb_populate(PathBuf *buf, u8 *path) {
-    strncpy((char*) &buf->mem[0], (char*) path, 254);
-    buf->p = 0;
+// Check if a path buffer is empty.
+bool pathbuf_is_empty(PathBuf *buf) {
+    return buf->mem[0] == 0;
+}
+
+// Check if a path buffer contains the path of the root directory.
+bool pathbuf_is_root(PathBuf *buf) {
+    return buf->mem[0] == '/' && buf->mem[1] == 0;
+}
+
+// Check if a path buffer contains a valid path.
+bool pathbuf_is_valid(PathBuf *buf) {
+    // Test that path begins with a forward slash and ends with a null byte.
+    if (buf->mem[0x00] != '/') return false;
+    if (buf->mem[0xFF] !=  0 ) return false;
+    // Find the length of the path.
+    int len = 0;
+    for (; len<256; len++) if (buf->mem[len] == 0) break;
+    // End early if path is the root directory.
+    if (len == 1) return true;
+    // Test that path contains no control characters.
+    for (int i=0; i<len; i++) if (buf->mem[i] < 0x20) return false;
+    // Test that path contains no empty or relative components. This also
+    // happens to test that it doesn't end with a slash.
+    bool is_empty = false;
+    bool all_dots = false;
+    int dot_count = 0;
+    u8 c;
+    for (int i=0; i<=len; i++) {
+        c = buf->mem[i];
+        if (c == '/' || c == 0) {
+            // Test if component is empty.
+            if (is_empty) return false;
+            // Test if component is one or two periods.
+            if (all_dots && dot_count < 3) return false;
+            // Reset flags.
+            is_empty = true;
+            all_dots = true;
+            dot_count = 0;
+        } else {
+            is_empty = false;
+            if (c == '.') {
+                dot_count++;
+            } else {
+                all_dots = false;
+            }
+        }
+    }
+    return true;
 }