1 files changed, 55 insertions, 0 deletions
diff --git a/neozip/arch/generic/adler32_c.c b/neozip/arch/generic/adler32_c.c
new file mode 100644
index 0000000000..84c946f452
--- /dev/null
+++ b/neozip/arch/generic/adler32_c.c
@@ -0,0 +1,55 @@
+/* adler32.c -- compute the Adler-32 checksum of a data stream
+ * Copyright (C) 1995-2011, 2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "zbuild.h"
+#include "functable.h"
+#include "adler32_p.h"
+
+Z_INTERNAL uint32_t adler32_c(uint32_t adler, const uint8_t *buf, size_t len) {
+    uint32_t sum2;
+    unsigned n;
+
+    /* split Adler-32 into component sums */
+    sum2 = (adler >> 16) & 0xffff;
+    adler &= 0xffff;
+
+    /* in case user likes doing a byte at a time, keep it fast */
+    if (UNLIKELY(len == 1))
+        return adler32_copy_tail(adler, NULL, buf, 1, sum2, 1, 1, 0);
+
+    /* in case short lengths are provided, keep it somewhat fast */
+    if (UNLIKELY(len < 16))
+        return adler32_copy_tail(adler, NULL, buf, len, sum2, 1, 15, 0);
+
+    /* do length NMAX blocks -- requires just one modulo operation */
+    while (len >= NMAX) {
+        len -= NMAX;
+#ifdef UNROLL_MORE
+        n = NMAX / 16;          /* NMAX is divisible by 16 */
+#else
+        n = NMAX / 8;           /* NMAX is divisible by 8 */
+#endif
+        do {
+#ifdef UNROLL_MORE
+            ADLER_DO16(adler, sum2, buf);          /* 16 sums unrolled */
+            buf += 16;
+#else
+            ADLER_DO8(adler, sum2, buf, 0);         /* 8 sums unrolled */
+            buf += 8;
+#endif
+        } while (--n);
+        adler %= BASE;
+        sum2 %= BASE;
+    }
+
+    /* do remaining bytes (less than NMAX, still just one modulo) */
+    return adler32_copy_tail(adler, NULL, buf, len, sum2, len != 0, NMAX - 1, 0);
+}
+
+Z_INTERNAL uint32_t adler32_copy_c(uint32_t adler, uint8_t *dst, const uint8_t *src, size_t len) {
+    adler = FUNCTABLE_CALL(adler32)(adler, src, len);
+    memcpy(dst, src, len);
+    return adler;
+}