feat|perf: generic&efficient desktop&config parser

src/desktop.c

@@ -0,0 +1,74 @@
+// NOLINTBEGIN(clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling,readability-function-cognitive-complexity)
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "desktop.h"
+#include "macros.h"
+
+#define NOK   \
+  {           \
+    ret = -1; \
+    break;    \
+  }
+#define NOKFKEY \
+  {             \
+    free(key);  \
+    NOK         \
+  }
+int read_desktop(FILE* fd, void* ctx,
+                 struct status (*cb)(void* ctx, char* NULLABLE table, char* key,
+                                     char* value)) {
+  char* table_name = NULL;
+
+  bool ret = -1;
+  char* buf = NULL;
+  size_t alloc_size = 0;
+  size_t read_size;
+  while ((read_size = getline(&buf, &alloc_size, fd)) > 0) {
+    ret = 0;
+
+    if (read_size <= 1) continue;
+
+    if (buf[0] == '[' && buf[read_size - 2] == ']') {
+      if (table_name != NULL) free(table_name);
+      table_name = realloc(buf, read_size);
+      table_name[read_size - 1] = '\0'; // newline
+      buf = NULL;
+      alloc_size = 0;
+    } else {
+      // Find '='
+      size_t eq_idx = 0;
+      while (buf[eq_idx] != '\0') {
+        if (buf[eq_idx] == '=') break;
+        eq_idx++;
+      }
+      // impossible with a min len of 1 (empty line)
+      if (eq_idx == 0) continue;
+      // Check its not end
+      if (buf[eq_idx] != '=') NOK;
+
+      // Key & Value
+      char* key = buf;
+      buf[eq_idx] = '\0'; // the equal
+      char* value = &buf[eq_idx+1];
+      buf[read_size-1] = '\0'; // the newline
+
+      // Callback
+      struct status cb_ret = cb(ctx, table_name, key, value);
+      if (cb_ret.finish) {
+        ret = cb_ret.ret;
+        break;
+      }
+    }
+  }
+
+  free(table_name);
+
+  if (buf != NULL) free(buf);
+  return ret;
+}
+#undef NOK
+#undef NOKFKEY
+// NOLINTEND(clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling,readability-function-cognitive-complexity)