Merge remote-tracking branch 'origin/master'

1 files changed, 94 insertions, 0 deletions

diff --git a/impl/vec.c b/impl/vec.c
new file mode 100644
index 0000000..12f577c
--- /dev/null
+++ b/impl/vec.c
@@ -0,0 +1,94 @@
+/* Copyright (C) 2025 Aryadev Chavali
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the Unlicense
+ * for details.
+
+ * You may distribute and modify this code under the terms of the
+ * Unlicense, which you should have received a copy of along with this
+ * program.  If not, please go to <https://unlicense.org/>.
+
+ * Created: 2025-08-20
+ * Description: Stable Vector implementation
+ */
+
+#include <malloc.h>
+#include <string.h>
+
+#include <alisp.h>
+
+void vec_init(vec_t *vec, u64 size)
+{
+  memset(vec, 0, sizeof(*vec));
+  if (!vec)
+    return;
+  else if (size <= VEC_INLINE_CAPACITY)
+  {
+    vec->is_inlined = 1;
+    vec->capacity   = VEC_INLINE_CAPACITY;
+    vec->ptr        = NULL;
+  }
+  else
+  {
+    vec->is_inlined = 0;
+    vec->capacity   = size;
+    vec->ptr        = calloc(1, vec->capacity);
+  }
+}
+
+void vec_free(vec_t *vec)
+{
+  if (!vec)
+    return;
+  if (!vec->is_inlined && vec->ptr)
+    free(vec->ptr);
+  memset(vec, 0, sizeof(*vec));
+}
+
+void *vec_data(vec_t *vec)
+{
+  return vec->is_inlined ? vec->inlined : vec->ptr;
+}
+
+void vec_ensure_free(vec_t *vec, u64 size)
+{
+  if (!vec)
+    return;
+  if (vec->capacity - vec->size < size)
+  {
+    vec->capacity = MAX(vec->capacity * VEC_MULT, vec->size + size);
+    if (vec->is_inlined)
+    {
+      // If we're inlined, we need to allocate on the heap now.  So let's copy
+      // vec->inlined over to vec->ptr, then turn off inlining.
+
+      // We need to do a two-way swap since vec->ptr and vec->inlined are taking
+      // up the same space.
+      u8 buffer[VEC_INLINE_CAPACITY];
+      memcpy(buffer, vec->inlined, vec->size);
+      vec->ptr = calloc(1, vec->capacity);
+      memcpy(vec->ptr, buffer, vec->size);
+      vec->is_inlined = 0;
+    }
+    else
+      vec->ptr = realloc(vec->ptr, vec->capacity);
+  }
+}
+
+void vec_append(vec_t *vec, const void *const ptr, u64 size)
+{
+  if (!vec)
+    return;
+  vec_ensure_free(vec, size);
+  memcpy(vec_data(vec) + vec->size, ptr, size);
+  vec->size += size;
+}
+
+void vec_clone(vec_t *dest, vec_t *src)
+{
+  if (!src || !dest)
+    return;
+  vec_init(dest, src->capacity);
+  memcpy(vec_data(dest), vec_data(src), src->size);
+}