From: Yuriy Skalko <yuriy.skalko@gmail.com>
Date: Sat, 26 Dec 2020 19:23:44 +0000 (+0200)
Subject: Use crc32 calculation from zlib instead of boost
X-Git-Tag: 2.4.0-alpha3~426
X-Git-Url: https://git.lyx.org/gitweb/?a=commitdiff_plain;h=197ea636;p=lyx.git

Use crc32 calculation from zlib instead of boost
---

diff --git a/src/support/FileName.cpp b/src/support/FileName.cpp
index 3d31c7d37c..5295741e1a 100644
--- a/src/support/FileName.cpp
+++ b/src/support/FileName.cpp
@@ -608,8 +608,8 @@ unsigned long FileName::checksum() const
 		return 0;
 	}
 
-	char * beg = static_cast<char*>(mm);
-	char * end = beg + info.st_size;
+	unsigned char * beg = static_cast<unsigned char*>(mm);
+	unsigned char * end = beg + info.st_size;
 
 	result = support::checksum(beg, end);
 
diff --git a/src/support/checksum.cpp b/src/support/checksum.cpp
index 79ef955ce3..2249ad14e0 100644
--- a/src/support/checksum.cpp
+++ b/src/support/checksum.cpp
@@ -9,9 +9,10 @@
  * Full author contact details are available in file CREDITS.
  */
 
+#include <config.h>
 #include "support/checksum.h"
-#include "boost/crc.hpp"
-#include <algorithm>
+
+#include <zlib.h>
 
 namespace lyx {
 
@@ -19,9 +20,8 @@ namespace support {
 
 unsigned long checksum(std::string const & s)
 {
-	boost::crc_32_type crc;
-	crc.process_bytes(s.c_str(), s.size());
-	return crc.checksum();
+	auto p = reinterpret_cast<unsigned char const *>(s.c_str());
+	return crc32(0, p, s.size());
 }
 
 unsigned long checksum(std::ifstream & ifs)
@@ -29,16 +29,17 @@ unsigned long checksum(std::ifstream & ifs)
 	std::istreambuf_iterator<char> beg(ifs);
 	std::istreambuf_iterator<char> end;
 
-	boost::crc_32_type crc;
-	crc = for_each(beg, end, crc);
-	return crc.checksum();
+	unsigned long sum = 0;
+	for (auto & it = beg; beg != end; ++it) {
+		unsigned char c = *it;
+		sum = crc32(sum, &c, 1);
+	}
+	return sum;
 }
 
-unsigned long checksum(char const * beg, char const * end)
+unsigned long checksum(unsigned char const * beg, unsigned char const * end)
 {
-	boost::crc_32_type crc;
-	crc.process_block(beg, end);
-	return crc.checksum();
+	return crc32(0, beg, end - beg);
 }
 
 } // namespace support
diff --git a/src/support/checksum.h b/src/support/checksum.h
index ab14339765..0533c57d79 100644
--- a/src/support/checksum.h
+++ b/src/support/checksum.h
@@ -21,7 +21,7 @@ namespace support {
 
 unsigned long checksum(std::string const & s);
 unsigned long checksum(std::ifstream & ifs);
-unsigned long checksum(char const * beg, char const * end);
+unsigned long checksum(unsigned char const * beg, unsigned char const * end);
 
 } // namespace support