introduce incremental md5 digester

Signed-off-by: Michael Krelin <hacker@klever.net>

1 files changed, 14 insertions, 0 deletions

diff --git a/src/eyetil.cc b/src/eyetil.cc
index 7669cb6..57ae607 100644
--- a/src/eyetil.cc
+++ b/src/eyetil.cc
@@ -61,24 +61,38 @@ std::string binary_t::hex() const {
     return rv;
 }
 
 binary_t binary_t::md5() const {
     binary_t rv(MD5_DIGEST_LENGTH);
     if(!MD5(
 		(const unsigned char*)&(front()),size(),
 		(unsigned char*)&(rv.front()) ))
 	throw std::runtime_error("failed to md5()");
     return rv;
 }
 
+void md5_digester::init() {
+    if(!MD5_Init(&ctx)) throw std::runtime_error("failed to MD5_Init()");
+}
+void md5_digester::update(const void *d,size_t l) {
+    if(!MD5_Update(&ctx,d,l)) throw std::runtime_error("failed to MD5_Update()");
+}
+binary_t md5_digester::final() {
+    binary_t rv(MD5_DIGEST_LENGTH);
+    if(!MD5_Final((unsigned char*)&(rv.front()), &ctx))
+	throw std::runtime_error("failed to MD5_Final()");
+    return rv;
+}
+
+
 static void make_path_for_template(const std::string& p,mode_t m) {
     struct stat st;
     std::string pp;
     for(std::string::size_type sl=p.find('/',1);
 	    sl!=std::string::npos;
 	    sl=p.find('/',sl+1)) {
 	if(stat( (pp=p.substr(0,sl)).c_str() ,&st)
 		|| !S_ISDIR(st.st_mode)) {
 	    if(mkdir(pp.c_str(),m))
 		throw std::runtime_error("failed to mkdir()");
 	}
     }