Implement path normalization for file browser

Author: rexim

src/common.c

@@ -16,6 +16,8 @@
 #include "common.h"
 #define ARENA_IMPLEMENTATION
 #include "./arena.h"
+#define SV_IMPLEMENTATION
+#include "sv.h"
 
 static Arena temporary_arena = {0};
 

src/common.h

@@ -32,6 +32,16 @@ typedef int Errno;
 
 #define DA_INIT_CAP 256
 
+#define da_last(da) (assert((da)->count > 0), (da)->items[(da)->count - 1])
+
+#define da_move(dst, src)                \
+    do {                                 \
+       free((dst)->items);               \
+       (dst)->items = (src).items;       \
+       (dst)->count = (src).count;       \
+       (dst)->capacity = (src).capacity; \
+    } while (0)
+
 #define da_append(da, item)                                                          \
     do {                                                                             \
         if ((da)->count >= (da)->capacity) {                                         \
@@ -68,6 +78,9 @@ typedef struct {
     size_t capacity;
 } String_Builder;
 
+#define SB_Fmt "%.*s"
+#define SB_Arg(sb) (int) (sb).count, (sb).items
+
 #define sb_append_buf da_append_many
 #define sb_append_cstr(sb, cstr)  \
     do {                          \
@@ -77,6 +90,8 @@ typedef struct {
     } while (0)
 #define sb_append_null(sb) da_append_many(sb, "", 1)
 
+#define sb_to_sv(sb) sv_from_parts((sb).items, (sb).count)
+
 typedef struct {
     const char **items;
     size_t count;

src/file_browser.c

@@ -1,5 +1,6 @@
 #include <string.h>
 #include "file_browser.h"
+#include "sv.h"
 
 static int file_cmp(const void *ap, const void *bp)
 {
@@ -25,6 +26,76 @@ Errno fb_open_dir(File_Browser *fb, const char *dir_path)
     return 0;
 }
 
+#define PATH_SEP "/"
+#define PATH_EMPTY ""
+#define PATH_DOT "."
+#define PATH_DOTDOT ".."
+
+typedef struct {
+    String_View *items;
+    size_t count;
+    size_t capacity;
+} Comps;
+
+void normpath(String_View path, String_Builder *result)
+{
+    size_t original_sb_size = result->count;
+
+    if (path.count == 0) {
+        sb_append_cstr(result, PATH_DOT);
+        return;
+    }
+
+    int initial_slashes = 0;
+    while (path.count > 0 && *path.data == *PATH_SEP) {
+        initial_slashes += 1;
+        sv_chop_left(&path, 1);
+    }
+    if (initial_slashes > 2) {
+        initial_slashes = 1;
+    }
+
+    Comps new_comps = {0};
+
+    while (path.count > 0) {
+        String_View comp = sv_chop_by_delim(&path, '/');
+        if (comp.count == 0 || sv_eq(comp, SV(PATH_DOT))) {
+            continue;
+        }
+        if (!sv_eq(comp, SV(PATH_DOTDOT))) {
+            da_append(&new_comps, comp);
+            continue;
+        }
+        if (initial_slashes == 0 && new_comps.count == 0) {
+            da_append(&new_comps, comp);
+            continue;
+        }
+        if (new_comps.count > 0 && sv_eq(da_last(&new_comps), SV(PATH_DOTDOT))) {
+            da_append(&new_comps, comp);
+            continue;
+        }
+        if (new_comps.count > 0) {
+            new_comps.count -= 1;
+            continue;
+        }
+    }
+
+    for (int i = 0; i < initial_slashes; ++i) {
+        sb_append_cstr(result, PATH_SEP);
+    }
+
+    for (size_t i = 0; i < new_comps.count; ++i) {
+        if (i > 0) sb_append_cstr(result, PATH_SEP);
+        sb_append_buf(result, new_comps.items[i].data, new_comps.items[i].count);
+    }
+
+    if (original_sb_size == result->count) {
+        sb_append_cstr(result, PATH_DOT);
+    }
+
+    free(new_comps.items);
+}
+
 Errno fb_change_dir(File_Browser *fb)
 {
     assert(fb->dir_path.count > 0 && "You need to call fb_open_dir() before fb_change_dir()");
@@ -36,11 +107,17 @@ Errno fb_change_dir(File_Browser *fb)
 
     fb->dir_path.count -= 1;
 
-    // TODO: fb_change_dir() does not support .. and . properly
+    // TODO: fb->dir_path grows indefinitely if we hit the root
     sb_append_cstr(&fb->dir_path, "/");
     sb_append_cstr(&fb->dir_path, dir_name);
+
+    String_Builder result = {0};
+    normpath(sb_to_sv(fb->dir_path), &result);
+    da_move(&fb->dir_path, result);
     sb_append_null(&fb->dir_path);
 
+    printf("Changed dir to %s\n", fb->dir_path.items);
+
     fb->files.count = 0;
     fb->cursor = 0;
     Errno err = read_entire_dir(fb->dir_path.items, &fb->files);

src/main.c

@@ -20,6 +20,7 @@
 #include "./simple_renderer.h"
 #include "./common.h"
 #include "./lexer.h"
+#include "./sv.h"
 
 // TODO: Save file dialog
 // Needed when ded is ran without any file so it does not know where to save.
@@ -55,6 +56,7 @@ static File_Browser fb = {0};
 // TODO: display errors reported via flash_error right in the text editor window somehow
 #define flash_error(...) do { fprintf(stderr, __VA_ARGS__); fprintf(stderr, "\n"); } while(0)
 
+
 int main(int argc, char **argv)
 {
     Errno err;
@@ -294,19 +296,22 @@ int main(int argc, char **argv)
                         for (size_t i = 0; i < 4; ++i) {
                             editor_insert_char(&editor, ' ');
                         }
-                    } break;
+                    }
+                    break;
 
                     case SDLK_c: {
                         if (event.key.keysym.mod & KMOD_CTRL) {
                             editor_clipboard_copy(&editor);
                         }
-                    } break;
+                    }
+                    break;
 
                     case SDLK_v: {
                         if (event.key.keysym.mod & KMOD_CTRL) {
                             editor_clipboard_paste(&editor);
                         }
-                    } break;
+                    }
+                    break;
 
                     case SDLK_UP: {
                         editor_update_selection(&editor, event.key.keysym.mod & KMOD_SHIFT);