Update dstr to use Arena

2024-04-29 22:48:10 +01:00
parent 05e56d67ea
commit e75846a507
2 changed files with 37 additions and 89 deletions
--- a/src/strings/dstr/dstr.c
+++ b/src/strings/dstr/dstr.c
@@ -0,0 +1,174 @@
+#include "dstr.h"
+#include "aliases.h"
+#include "mem_arena.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+// Use this scalar to allocate extra memory in order to avoid having to
+// constantly reallocate
+#define CAPACITY_SCALAR 8
+#define MINIMUM_DSTR_CAPACITY 1024
+
+struct dstr {
+  u64 capacity;
+  u64 size;
+  char buf[];
+};
+
+String *wapp_dstr_with_capacity(u64 capacity, Arena *arena) {
+  if (!arena) {
+    return NULL;
+  }
+
+  String *out =
+      (String *)wapp_mem_arena_alloc(arena, sizeof(String) + capacity + 1);
+  if (!out) {
+    return NULL;
+  }
+
+  out->capacity = capacity;
+  out->size = 0;
+
+  return out;
+}
+
+String *wapp_dstr_from_string(const char *str, Arena *arena) {
+  if (!str || !arena) {
+    return NULL;
+  }
+
+  u64 length = strlen(str);
+  u64 capacity = length * CAPACITY_SCALAR;
+  capacity =
+      capacity >= MINIMUM_DSTR_CAPACITY ? capacity : MINIMUM_DSTR_CAPACITY;
+
+  String *out = wapp_dstr_with_capacity(capacity, arena);
+  if (!out) {
+    return NULL;
+  }
+
+  out->size = length;
+  strncpy(out->buf, str, length + 1);
+
+  return out;
+}
+
+String *wapp_dstr_update(String **dst, const char *src, Arena *arena) {
+  if (!dst || !(*dst)) {
+    return *dst;
+  }
+
+  u64 length = strlen(src);
+
+  String *str = *dst;
+
+  if (length >= str->capacity) {
+    if (!arena) {
+      return *dst;
+    }
+
+    String *new_str = wapp_dstr_from_string(src, arena);
+    if (!new_str) {
+      return *dst;
+    }
+
+    return new_str;
+  }
+
+  memset(str->buf, 0, str->capacity);
+
+  str->size = length;
+
+  strncpy(str->buf, src, length + 1);
+
+  return *dst;
+}
+
+String *wapp_dstr_concat(String **dst, const char *src, Arena *arena) {
+  if (!dst || !(*dst)) {
+    return *dst;
+  }
+
+  u64 src_length = strlen(src);
+  if (src_length == 0) {
+    return *dst;
+  }
+
+  u64 new_length = (*dst)->size + src_length;
+
+  char str[new_length + 1];
+  memset(str, 0, new_length + 1);
+
+  strncpy(str, (*dst)->buf, (*dst)->size);
+  strncat(str, src, new_length + 1 - (*dst)->size);
+
+  return wapp_dstr_update(dst, str, arena);
+}
+
+void wapp_dstr_clear(String *str) {
+  if (!str || str->size == 0) {
+    return;
+  }
+
+  memset(str->buf, 0, str->capacity);
+  str->size = 0;
+}
+
+void wapp_dstr_print(const String *str) {
+  if (!str) {
+    return;
+  }
+
+  printf("%.*s\n", (i32)str->size, str->buf);
+}
+
+i64 wapp_dstr_find(const String *str, const char *substr) {
+  if (!str || !substr) {
+    return -1;
+  }
+
+  u64 substr_length = strlen(substr);
+  if (substr_length == 0 || substr_length > str->size) {
+    return -1;
+  }
+
+  const char *s1;
+  for (u64 i = 0; i < str->size; ++i) {
+    if (i + substr_length > str->size) {
+      break;
+    }
+
+    s1 = &(str->buf[i]);
+
+    if (strncmp(s1, substr, substr_length) == 0) {
+      return i;
+    }
+  }
+
+  return -1;
+}
+
+u64 wapp_dstr_length(const String *str) {
+  if (!str) {
+    return 0;
+  }
+
+  return str->size;
+}
+
+u64 wapp_dstr_capacity(const String *str) {
+  if (!str) {
+    return 0;
+  }
+
+  return str->capacity;
+}
+
+const char *wapp_dstr_to_cstr(const String *str) {
+  if (!str) {
+    return "";
+  }
+
+  return str->buf;
+}