From d50dc288cd6cbd83528e1e9e1c108e1cdb6a388e Mon Sep 17 00:00:00 2001
From: cpq <valenok@gmail.com>
Date: Mon, 8 Mar 2021 15:40:39 +0000
Subject: [PATCH] Add mg_crc32

---
 src/util.c | 10 ++++++++++
 src/util.h |  1 +
 2 files changed, 11 insertions(+)

diff --git a/src/util.c b/src/util.c
index 2df5124a..8ea74ccd 100644
--- a/src/util.c
+++ b/src/util.c
@@ -273,6 +273,16 @@ int64_t mg_to64(struct mg_str str) {
   return result * neg;
 }
 
+uint32_t mg_crc32(uint32_t crc, const char *buf, size_t len) {
+  int i;
+  crc = ~crc;
+  while (len--) {
+    crc ^= *(unsigned char *) buf++;
+    for (i = 0; i < 8; i++) crc = crc & 1 ? (crc >> 1) ^ 0xedb88320 : crc >> 1;
+  }
+  return ~crc;
+}
+
 double mg_time(void) {
 #if MG_ARCH == MG_ARCH_WIN32
   SYSTEMTIME sysnow;
diff --git a/src/util.h b/src/util.h
index 52f243a3..1e172cf1 100644
--- a/src/util.h
+++ b/src/util.h
@@ -12,6 +12,7 @@ bool mg_globmatch(const char *pattern, int plen, const char *s, int n);
 bool mg_next_comma_entry(struct mg_str *s, struct mg_str *k, struct mg_str *v);
 uint16_t mg_ntohs(uint16_t net);
 uint32_t mg_ntohl(uint32_t net);
+uint32_t mg_crc32(uint32_t crc, const char *buf, size_t len);
 char *mg_hexdump(const void *buf, size_t len);
 char *mg_hex(const void *buf, int len, char *dst);
 void mg_unhex(const char *buf, int len, unsigned char *to);