wrap crc32 in functable (#145)

* wrap crc32 in functable
* change internal crc32 api to use uint64_t rather than size_t for length

1 files changed, 47 insertions, 1 deletions

diff --git a/functable.c b/functable.c
index 06dc41f..3921fc9 100644
--- a/functable.c
+++ b/functable.c
@@ -7,6 +7,8 @@
 #include "deflate.h"
 #include "deflate_p.h"
 
+#include "gzendian.h"
+
 #if defined(X86_CPUID)
 # include "arch/x86/x86.h"
 #endif
@@ -32,13 +34,26 @@ extern uint32_t adler32_c(uint32_t adler, const unsigned char *buf, size_t len);
 extern uint32_t adler32_neon(uint32_t adler, const unsigned char *buf, size_t len);
 #endif
 
+ZLIB_INTERNAL uint32_t crc32_generic(uint32_t, const unsigned char *, uint64_t);
+
+#ifdef __ARM_FEATURE_CRC32
+extern uint32_t crc32_acle(uint32_t, const unsigned char *, uint64_t);
+#endif
+
+#if BYTE_ORDER == LITTLE_ENDIAN
+extern uint32_t crc32_little(uint32_t, const unsigned char *, uint64_t);
+#elif BYTE_ORDER == BIG_ENDIAN
+extern uint32_t crc32_big(uint32_t, const unsigned char *, uint64_t);
+#endif
+
 /* stub definitions */
 ZLIB_INTERNAL Pos insert_string_stub(deflate_state *const s, const Pos str, unsigned int count);
 ZLIB_INTERNAL void fill_window_stub(deflate_state *s);
 ZLIB_INTERNAL uint32_t adler32_stub(uint32_t adler, const unsigned char *buf, size_t len);
+ZLIB_INTERNAL uint32_t crc32_stub(uint32_t crc, const unsigned char *buf, uint64_t len);
 
 /* functable init */
-ZLIB_INTERNAL struct functable_s functable = {fill_window_stub,insert_string_stub,adler32_stub};
+ZLIB_INTERNAL struct functable_s functable = {fill_window_stub,insert_string_stub,adler32_stub,crc32_stub};
 
 
 /* stub functions */
@@ -82,3 +97,34 @@ ZLIB_INTERNAL uint32_t adler32_stub(uint32_t adler, const unsigned char *buf, si
 
     return functable.adler32(adler, buf, len);
 }
+
+ZLIB_INTERNAL uint32_t crc32_stub(uint32_t crc, const unsigned char *buf, uint64_t len) {
+
+
+   Assert(sizeof(uint64_t) >= sizeof(size_t),
+          "crc32_z takes size_t but internally we have a uint64_t len");
+/* return a function pointer for optimized arches here after a capability test */
+
+#ifdef DYNAMIC_CRC_TABLE
+    if (crc_table_empty)
+        make_crc_table();
+#endif /* DYNAMIC_CRC_TABLE */
+
+    if (sizeof(void *) == sizeof(ptrdiff_t)) {
+#if BYTE_ORDER == LITTLE_ENDIAN
+#  if __ARM_FEATURE_CRC32
+        functable.crc32=crc32_acle;
+#  else
+        functable.crc32=crc32_little;
+#  endif
+#elif BYTE_ORDER == BIG_ENDIAN
+        functable.crc32=crc32_big;
+#else
+#  error No endian defined
+#endif
+    } else {
+        functable.crc32=crc32_generic;
+    }
+
+    return functable.crc32(crc, buf, len);
+}