add mruby sources

1 files changed, 152 insertions, 0 deletions

diff --git a/src/pool.c b/src/pool.c
new file mode 100644
index 000000000..62e1a4d17
--- /dev/null
+++ b/src/pool.c
@@ -0,0 +1,152 @@
+#include "pool.h"
+#include <string.h>
+
+#undef TEST_POOL
+#ifdef TEST_POOL
+#include <stdio.h>
+
+#define mrb_malloc(m,s) malloc(s)
+#define mrb_free(m,p) free(p)
+#endif
+
+#define POOL_PAGE_SIZE 16000
+
+mrb_pool*
+mrb_pool_open(mrb_state *mrb)
+{
+  mrb_pool *pool = mrb_malloc(mrb, sizeof(mrb_pool));
+
+  if (pool) {
+    pool->mrb = mrb;
+    pool->pages = 0;
+  }
+
+  return pool;
+}
+
+void
+mrb_pool_close(mrb_pool *pool)
+{
+  struct mrb_pool_page *page, *tmp;
+
+  if (!pool) return;
+  page = pool->pages;
+  while (page) {
+    tmp = page;
+    page = page->next;
+    mrb_free(pool->mrb, tmp);
+  }
+  mrb_free(pool->mrb, pool);
+}
+
+static struct mrb_pool_page*
+page_alloc(mrb_pool *pool, size_t len)
+{
+  struct mrb_pool_page *page;
+
+  if (len < POOL_PAGE_SIZE)
+    len = POOL_PAGE_SIZE;
+  page = mrb_malloc(pool->mrb, sizeof(struct mrb_pool_page)+len-1);
+  if (page) {
+    page->offset = 0;
+    page->len = len;
+  }
+
+  return page;
+}
+
+void*
+mrb_pool_alloc(mrb_pool *pool, size_t len)
+{
+  struct mrb_pool_page *page;
+  size_t n;
+
+  if (!pool) return 0;
+
+  page = pool->pages;
+  while (page) {
+    if (page->offset + len <= page->len) {
+      n = page->offset;
+      page->offset += len;
+      page->last = (void*)page->page+n;
+      return page->last;
+    }
+    page = page->next;
+  }
+  page = page_alloc(pool, len);
+  if (!page) return 0;
+  page->offset = len;
+  page->next = pool->pages;
+  pool->pages = page;
+
+  page->last = (void*)page->page;
+  return page->last;
+}
+
+int
+mrb_pool_can_realloc(mrb_pool *pool, void *p, size_t len)
+{
+  struct mrb_pool_page *page;
+
+  if (!pool) return 0;
+  page = pool->pages;
+  while (page) {
+    if (page->last == p) {
+      size_t beg;
+
+      beg = (char*)p - page->page;
+      if (beg + len > page->len) return 0;
+      return 1;
+    }
+    page = page->next;
+  }
+  return 0;
+}
+
+void*
+mrb_pool_realloc(mrb_pool *pool, void *p, size_t oldlen, size_t newlen)
+{
+  struct mrb_pool_page *page;
+  void *np;
+
+  if (!pool) return 0;
+  page = pool->pages;
+  while (page) {
+    if (page->last == p) {
+      size_t beg;
+
+      beg = (char*)p - page->page;
+      if (beg + oldlen != page->offset) break;
+      if (beg + newlen > page->len) {
+	page->offset = beg;
+	break;
+      }
+      page->offset = beg + newlen;
+      return p;
+    }
+    page = page->next;
+  }
+  np = mrb_pool_alloc(pool, newlen);
+  memcpy(np, p, oldlen);
+  return np;
+}
+
+#ifdef TEST_POOL
+int
+main()
+{
+  int i, len = 250;
+  mrb_pool *pool;
+  void *p;
+
+  pool = mrb_pool_open(0);
+  p = mrb_pool_alloc(pool, len);
+  for (i=1; i<20; i++) {
+    printf("%p (len=%d) %d\n", p, len, mrb_pool_can_realloc(pool, p, len*2));
+    p = mrb_pool_realloc(pool, p, len, len*2);
+    len *= 2;
+  }
+  mrb_pool_close(pool);
+  return 0;
+}
+#endif