add getModulo for buf

5 files changed, 48 insertions, 2 deletions

diff --git a/include/mcl/fp.hpp b/include/mcl/fp.hpp
index 4ee59e4..6c39d1f 100644
--- a/include/mcl/fp.hpp
+++ b/include/mcl/fp.hpp
@@ -134,6 +134,10 @@ public:
 		mpz_class p(mstr);
 		init(p, mode);
 	}
+	static inline size_t getModulo(char *buf, size_t bufSize)
+	{
+		return gmp::getStr(buf, bufSize, op_.mp);
+	}
 	static inline void getModulo(std::string& pstr)
 	{
 		gmp::getStr(pstr, op_.mp);
diff --git a/include/mcl/gmp_util.hpp b/include/mcl/gmp_util.hpp
index 78cafc1..47c1ab8 100644
--- a/include/mcl/gmp_util.hpp
+++ b/include/mcl/gmp_util.hpp
@@ -112,6 +112,23 @@ inline bool setStr(mpz_class& z, const std::string& str, int base = 0)
 	return z.set_str(str, base) == 0;
 #endif
 }
+/*
+	set buf with string terminated by '\0'
+	return strlen(buf) if success else 0
+*/
+inline size_t getStr(char *buf, size_t bufSize, const mpz_class& z, int base = 10)
+{
+#ifdef MCL_USE_VINT
+	return z.getStr(buf, bufSize, base);
+#else
+	std::string str = z.get_str(base);
+	if (str.size() < bufSize) {
+		memcpy(buf, str.c_str(), str.size() + 1);
+		return str.size();
+	}
+	return 0;
+#endif
+}
 inline void getStr(std::string& str, const mpz_class& z, int base = 10)
 {
 #ifdef MCL_USE_VINT
diff --git a/include/mcl/vint.hpp b/include/mcl/vint.hpp
index ad1699b..5530b46 100644
--- a/include/mcl/vint.hpp
+++ b/include/mcl/vint.hpp
@@ -1109,7 +1109,7 @@ public:
 	}
 	void clear() { *this = 0; }
 	template<class OutputStream>
-	void save(OutputStream& os, int base, bool *pb) const
+	void save(bool *pb, OutputStream& os, int base = 10) const
 	{
 		if (isNeg_) cybozu::writeChar(pb, os, '-');
 		char buf[1024];
@@ -1124,9 +1124,23 @@ public:
 	void save(OutputStream& os, int base = 10) const
 	{
 		bool b;
-		save(os, base, &b);
+		save(&b, os, base);
 		if (!b) throw cybozu::Exception("Vint:save");
 	}
+	/*
+		set buf with string terminated by '\0'
+		return strlen(buf) if success else 0
+	*/
+	size_t getStr(char *buf, size_t bufSize, int base = 10) const
+	{
+		cybozu::MemoryOutputStream os(buf, bufSize);
+		bool b;
+		save(&b, os, base);
+		const size_t n = os.getPos();
+		if (!b || n == bufSize - 1) return 0;
+		buf[n] = '\0';
+		return n;
+	}
 	std::string getStr(int base = 10) const
 	{
 		std::string s;
diff --git a/test/fp_test.cpp b/test/fp_test.cpp
index b826971..f81e0c8 100644
--- a/test/fp_test.cpp
+++ b/test/fp_test.cpp
@@ -333,6 +333,10 @@ void compareTest()
 		}
 		std::string str;
 		Fp::getModulo(str);
+		char buf[1024];
+		size_t n = Fp::getModulo(buf, sizeof(buf));
+		CYBOZU_TEST_EQUAL(n, str.size());
+		CYBOZU_TEST_EQUAL(buf, str.c_str());
 		mpz_class half(str);
 		half = (half - 1) / 2;
 		Fp x;
diff --git a/test/vint_test.cpp b/test/vint_test.cpp
index a3ad8c1..0eea8a9 100644
--- a/test/vint_test.cpp
+++ b/test/vint_test.cpp
@@ -582,8 +582,15 @@ CYBOZU_TEST_AUTO(string)
 		Vint x, y;
 		x.setArray(tbl[i].v,tbl[i].vn);
 		CYBOZU_TEST_EQUAL(x.getStr(10), tbl[i].str);
+		char buf[1024];
+		size_t n = x.getStr(buf, sizeof(buf), 10);
+		CYBOZU_TEST_ASSERT(n > 0);
+		CYBOZU_TEST_EQUAL(tbl[i].str, buf);
 		y.setStr(tbl[i].str);
 		CYBOZU_TEST_EQUAL(x.getStr(16), tbl[i].hex + 2);
+		n = x.getStr(buf, sizeof(buf), 16);
+		CYBOZU_TEST_ASSERT(n > 0);
+		CYBOZU_TEST_EQUAL(tbl[i].hex + 2, buf);
 		CYBOZU_TEST_EQUAL(x, y);
 		x = 1;
 		x.setStr(tbl[i].hex);