From 3a3858dc908934be82ffe4f0d693ebb518397a28 Mon Sep 17 00:00:00 2001 From: moneromooo-monero Date: Mon, 26 Nov 2018 00:19:10 +0000 Subject: [PATCH] epee: avoid string allocation when parsing a pod from string --- contrib/epee/include/string_tools.h | 48 ++++++++--------------------- src/checkpoints/checkpoints.cpp | 4 +-- 2 files changed, 14 insertions(+), 38 deletions(-) diff --git a/contrib/epee/include/string_tools.h b/contrib/epee/include/string_tools.h index 6a063cc36..0d8eca727 100644 --- a/contrib/epee/include/string_tools.h +++ b/contrib/epee/include/string_tools.h @@ -117,16 +117,12 @@ namespace string_tools return to_hex::string(to_byte_span(to_span(src))); } //---------------------------------------------------------------------------- - template - bool parse_hexstr_to_binbuff(const std::basic_string& s, std::basic_string& res) + inline bool parse_hexstr_to_binbuff(const epee::span s, epee::span& res) { - res.clear(); - if (s.size() & 1) - return false; - try - { - res.resize(s.size() / 2); - unsigned char *dst = (unsigned char *)res.data(); + if (s.size() != res.size() * 2) + return false; + + unsigned char *dst = (unsigned char *)&res[0]; const unsigned char *src = (const unsigned char *)s.data(); for(size_t i = 0; i < s.size(); i += 2) { @@ -140,28 +136,15 @@ namespace string_tools } return true; - } - catch(...) - { - return false; - } } //---------------------------------------------------------------------------- - template - bool parse_tpod_from_hex_string(const std::string& str_hash, t_pod_type& t_pod) + inline bool parse_hexstr_to_binbuff(const std::string& s, std::string& res) { - static_assert(std::is_pod::value, "expected pod type"); - std::string buf; - bool res = epee::string_tools::parse_hexstr_to_binbuff(str_hash, buf); - if (!res || buf.size() != sizeof(t_pod_type)) - { + if (s.size() & 1) return false; - } - else - { - buf.copy(reinterpret_cast(&t_pod), sizeof(t_pod_type)); - return true; - } + res.resize(s.size() / 2); + epee::span rspan((char*)&res[0], res.size()); + return parse_hexstr_to_binbuff(epee::to_span(s), rspan); } //---------------------------------------------------------------------------- PUSH_WARNINGS @@ -360,17 +343,10 @@ POP_WARNINGS bool hex_to_pod(const std::string& hex_str, t_pod_type& s) { static_assert(std::is_pod::value, "expected pod type"); - std::string hex_str_tr = trim(hex_str); if(sizeof(s)*2 != hex_str.size()) return false; - std::string bin_buff; - if(!parse_hexstr_to_binbuff(hex_str_tr, bin_buff)) - return false; - if(bin_buff.size()!=sizeof(s)) - return false; - - s = *(t_pod_type*)bin_buff.data(); - return true; + epee::span rspan((char*)&s, sizeof(s)); + return parse_hexstr_to_binbuff(epee::to_span(hex_str), rspan); } //---------------------------------------------------------------------------- template diff --git a/src/checkpoints/checkpoints.cpp b/src/checkpoints/checkpoints.cpp index 1807d44d9..96f575b2d 100644 --- a/src/checkpoints/checkpoints.cpp +++ b/src/checkpoints/checkpoints.cpp @@ -74,7 +74,7 @@ namespace cryptonote bool checkpoints::add_checkpoint(uint64_t height, const std::string& hash_str) { crypto::hash h = crypto::null_hash; - bool r = epee::string_tools::parse_tpod_from_hex_string(hash_str, h); + bool r = epee::string_tools::hex_to_pod(hash_str, h); CHECK_AND_ASSERT_MES(r, false, "Failed to parse checkpoint hash string into binary representation!"); // return false if adding at a height we already have AND the hash is different @@ -292,7 +292,7 @@ namespace cryptonote // parse the second part as crypto::hash, // if this fails move on to the next record std::string hashStr = record.substr(pos + 1); - if (!epee::string_tools::parse_tpod_from_hex_string(hashStr, hash)) + if (!epee::string_tools::hex_to_pod(hashStr, hash)) { continue; }