Add ossl_str_new(), an exception-safe rb_str_new()

Add a new function ossl_str_new() as an exception-safe wrapper of
rb_str_new(). This is useful for the openssl library because we can't
always raise NoMemoryError immediately due to the independent memory
management of OpenSSL.

Author: rhenium

ext/openssl/ossl.c

@@ -92,22 +92,40 @@ OSSL_IMPL_SK2ARY(x509crl, X509_CRL)
 OSSL_IMPL_SK2ARY(x509name, X509_NAME)
 
 static VALUE
-ossl_str_new(int size)
+ossl_str_new_i(VALUE size)
 {
-    return rb_str_new(0, size);
+    return rb_str_new(NULL, (long)size);
+}
+
+VALUE
+ossl_str_new(const char *ptr, long len, int *pstate)
+{
+    VALUE str;
+    int state;
+
+    str = rb_protect(ossl_str_new_i, len, &state);
+    if (pstate)
+	*pstate = state;
+    if (state) {
+	if (!pstate)
+	    rb_set_errinfo(Qnil);
+	return Qnil;
+    }
+    if (ptr)
+	memcpy(RSTRING_PTR(str), ptr, len);
+    return str;
 }
 
 VALUE
 ossl_buf2str(char *buf, int len)
 {
     VALUE str;
-    int status = 0;
+    int state;
 
-    str = rb_protect((VALUE (*)(VALUE))ossl_str_new, len, &status);
-    if(!NIL_P(str)) memcpy(RSTRING_PTR(str), buf, len);
+    str = ossl_str_new(buf, len, &state);
     OPENSSL_free(buf);
-    if(status) rb_jump_tag(status);
-
+    if (state)
+	rb_jump_tag(state);
     return str;
 }
 

ext/openssl/ossl.h

@@ -92,6 +92,7 @@ VALUE ossl_x509_sk2ary(const STACK_OF(X509) *certs);
 VALUE ossl_x509crl_sk2ary(const STACK_OF(X509_CRL) *crl);
 VALUE ossl_x509name_sk2ary(const STACK_OF(X509_NAME) *names);
 VALUE ossl_buf2str(char *buf, int len);
+VALUE ossl_str_new(const char *, long, int *);
 #define ossl_str_adjust(str, p) \
 do{\
     long len = RSTRING_LEN(str);\