initial commit

src/core/ngx_crc32.h

@@ -0,0 +1,79 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ * Copyright (C) Nginx, Inc.
+ */
+
+
+#ifndef _NGX_CRC32_H_INCLUDED_
+#define _NGX_CRC32_H_INCLUDED_
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+
+
+extern uint32_t  *ngx_crc32_table_short;
+extern uint32_t   ngx_crc32_table256[];
+
+
+static ngx_inline uint32_t
+ngx_crc32_short(u_char *p, size_t len)
+{
+    u_char    c;
+    uint32_t  crc;
+
+    crc = 0xffffffff;
+
+    while (len--) {
+        c = *p++;
+        crc = ngx_crc32_table_short[(crc ^ (c & 0xf)) & 0xf] ^ (crc >> 4);
+        crc = ngx_crc32_table_short[(crc ^ (c >> 4)) & 0xf] ^ (crc >> 4);
+    }
+
+    return crc ^ 0xffffffff;
+}
+
+
+static ngx_inline uint32_t
+ngx_crc32_long(u_char *p, size_t len)
+{
+    uint32_t  crc;
+
+    crc = 0xffffffff;
+
+    while (len--) {
+        crc = ngx_crc32_table256[(crc ^ *p++) & 0xff] ^ (crc >> 8);
+    }
+
+    return crc ^ 0xffffffff;
+}
+
+
+#define ngx_crc32_init(crc)                                                   \
+    crc = 0xffffffff
+
+
+static ngx_inline void
+ngx_crc32_update(uint32_t *crc, u_char *p, size_t len)
+{
+    uint32_t  c;
+
+    c = *crc;
+
+    while (len--) {
+        c = ngx_crc32_table256[(c ^ *p++) & 0xff] ^ (c >> 8);
+    }
+
+    *crc = c;
+}
+
+
+#define ngx_crc32_final(crc)                                                  \
+    crc ^= 0xffffffff
+
+
+ngx_int_t ngx_crc32_table_init(void);
+
+
+#endif /* _NGX_CRC32_H_INCLUDED_ */