Cleaning wsrep-API dependencies from library code

Replace all wsrep_api.h dependencies with similar code
in library implementation.

Also add gcc/g++ 4.4 to travis automation to get better
compiler coverage.

src/CMakeLists.txt

@@ -15,5 +15,6 @@ add_library(wsrep-lib
   server_state.cpp
   thread.cpp
   transaction.cpp
+  uuid.cpp
   wsrep_provider_v26.cpp)
 target_link_libraries(wsrep-lib wsrep_api_v26 pthread dl)

src/gtid.cpp

@@ -36,11 +36,47 @@ std::istream& wsrep::operator>>(std::istream& is, wsrep::gtid& gtid)
     std::getline(is, id_str, ':');
     long long seq;
     is >> seq;
-    gtid = wsrep::gtid(wsrep::id(id_str), wsrep::seqno(seq));
+    if (!is)
+    {
+        is.clear(std::ios_base::failbit);
+        return is;
+    }
+    try
+    {
+        // wsrep::id constructor will throw if it cannot parse the
+        // id_str.
+        gtid = wsrep::gtid(wsrep::id(id_str), wsrep::seqno(seq));
+    }
+    catch (const wsrep::runtime_error& e)
+    {
+        // Formatting or extraction error. Clear the istream state and
+        // set failibit.
+        is.clear(std::ios_base::failbit);
+    }
     return is;
 }
 
-ssize_t wsrep::gtid_print_to_c_str(
+ssize_t wsrep::scan_from_c_str(
+    const char* buf, size_t buf_len, wsrep::gtid& gtid)
+{
+    std::istringstream is(std::string(buf, buf_len));
+    is >> gtid;
+    // Whole string was consumed without failures
+    if (is && is.eof())
+    {
+        return buf_len;
+    }
+    // Some failure occurred
+    if (!is)
+    {
+        return -EINVAL;
+    }
+    // The string was not consumed completely, return current position
+    // of the istream.
+    return is.tellg();
+}
+
+ssize_t wsrep::print_to_c_str(
     const wsrep::gtid& gtid, char* buf, size_t buf_len)
 {
     std::ostringstream os;

src/id.cpp

@@ -18,7 +18,7 @@
  */
 
 #include "wsrep/id.hpp"
-#include <wsrep_api.h>
+#include "uuid.hpp"
 
 #include <cctype>
 #include <sstream>
@@ -29,15 +29,17 @@ const wsrep::id wsrep::id::undefined_ = wsrep::id();
 wsrep::id::id(const std::string& str)
     :  data_()
 {
-    wsrep_uuid_t wsrep_uuid;
-    if (wsrep_uuid_scan(str.c_str(), str.size(), &wsrep_uuid) ==
-        WSREP_UUID_STR_LEN)
+    wsrep::uuid_t wsrep_uuid;
+
+    if (str.size() == WSREP_LIB_UUID_STR_LEN &&
+        wsrep::uuid_scan(str.c_str(), str.size(), &wsrep_uuid) ==
+        WSREP_LIB_UUID_STR_LEN)
     {
-        std::memcpy(data_, wsrep_uuid.data, sizeof(data_));
+        std::memcpy(data_.buf, wsrep_uuid.data, sizeof(data_.buf));
     }
     else if (str.size() <= 16)
     {
-        std::memcpy(data_, str.c_str(), str.size());
+        std::memcpy(data_.buf, str.c_str(), str.size());
     }
     else
     {
@@ -58,14 +60,14 @@ std::ostream& wsrep::operator<<(std::ostream& os, const wsrep::id& id)
     }
     else
     {
-        char uuid_str[WSREP_UUID_STR_LEN + 1];
-        wsrep_uuid_t uuid;
+        char uuid_str[WSREP_LIB_UUID_STR_LEN + 1];
+        wsrep::uuid_t uuid;
         std::memcpy(uuid.data, ptr, sizeof(uuid.data));
-        if (wsrep_uuid_print(&uuid, uuid_str, sizeof(uuid_str)) < 0)
+        if (wsrep::uuid_print(&uuid, uuid_str, sizeof(uuid_str)) < 0)
         {
             throw wsrep::runtime_error("Could not print uuid");
         }
-        uuid_str[WSREP_UUID_STR_LEN] = '\0';
+        uuid_str[WSREP_LIB_UUID_STR_LEN] = '\0';
         return (os << uuid_str);
     }
 }

src/uuid.cpp

@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2019 Codership Oy <info@codership.com>
+ *
+ * This file is part of wsrep-lib.
+ *
+ * Wsrep-lib is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * Wsrep-lib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with wsrep-lib.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "uuid.hpp"
+
+#include <cstring>
+#include <cerrno>
+#include <cstdio>
+#include <cctype>
+
+int wsrep::uuid_scan (const char* str, size_t str_len, wsrep::uuid_t* uuid)
+{
+    unsigned int uuid_len  = 0;
+    unsigned int uuid_offt = 0;
+
+    while (uuid_len + 1 < str_len) {
+        /* We are skipping potential '-' after uuid_offt == 4, 6, 8, 10
+         * which means
+         *     (uuid_offt >> 1) == 2, 3, 4, 5,
+         * which in turn means
+         *     (uuid_offt >> 1) - 2 <= 3
+         * since it is always >= 0, because uuid_offt is unsigned */
+        if (((uuid_offt >> 1) - 2) <= 3 && str[uuid_len] == '-') {
+            // skip dashes after 4th, 6th, 8th and 10th positions
+            uuid_len += 1;
+            continue;
+        }
+
+        if (isxdigit(str[uuid_len]) && isxdigit(str[uuid_len + 1])) {
+            // got hex digit, scan another byte to uuid, increment uuid_offt
+            sscanf (str + uuid_len, "%2hhx", uuid->data + uuid_offt);
+            uuid_len  += 2;
+            uuid_offt += 1;
+            if (sizeof (uuid->data) == uuid_offt)
+                return uuid_len;
+        }
+        else {
+            break;
+        }
+    }
+
+    *uuid = wsrep::uuid_initializer;
+    return -EINVAL;
+}
+
+int wsrep::uuid_print (const wsrep::uuid_t* uuid, char* str, size_t str_len)
+{
+    if (str_len > WSREP_LIB_UUID_STR_LEN) {
+        const unsigned char* u = uuid->data;
+        return snprintf(str, str_len, "%02x%02x%02x%02x-%02x%02x-%02x%02x-"
+                        "%02x%02x-%02x%02x%02x%02x%02x%02x",
+                        u[ 0], u[ 1], u[ 2], u[ 3], u[ 4], u[ 5], u[ 6], u[ 7],
+                        u[ 8], u[ 9], u[10], u[11], u[12], u[13], u[14], u[15]);
+    }
+    else {
+        return -EMSGSIZE;
+    }
+}

src/uuid.hpp

@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2019 Codership Oy <info@codership.com>
+ *
+ * This file is part of wsrep-lib.
+ *
+ * Wsrep-lib is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * Wsrep-lib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with wsrep-lib.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/** @file uuid.hpp
+ *
+ * Helper methods to parse and print UUIDs, intended to use
+ * internally in wsrep-lib.
+ *
+ * The implementation is copied from wsrep-API v26.
+ */
+
+#ifndef WSREP_UUID_HPP
+#define WSREP_UUID_HPP
+
+#include "wsrep/compiler.hpp"
+
+#include <cstddef>
+
+/**
+ * Length of UUID string representation, not including terminating '\0'.
+ */
+#define WSREP_LIB_UUID_STR_LEN 36
+
+namespace wsrep
+{
+    /**
+     * UUID type.
+     */
+    typedef union uuid_
+    {
+        unsigned char data[16];
+        size_t alignment;
+    } uuid_t;
+
+    static const wsrep::uuid_t uuid_initializer = {{0, }};
+
+    /**
+     * Read UUID from string.
+     *
+     * @param str String to read from
+     * @param str_len Length of string
+     * @param[out] UUID to read to
+     *
+     * @return Number of bytes read or negative error code in case
+     *         of error.
+     */
+    int uuid_scan(const char* str, size_t str_len, wsrep::uuid_t* uuid);
+
+    /**
+     * Write UUID to string. The caller must allocate at least
+     * WSREP_LIB_UUID_STR_LEN + 1 space for the output str parameter.
+     *
+     * @param uuid UUID to print
+     * @param str[out] Output buffer
+     * @param str_len Size of output buffer
+     *
+     * @return Number of chars printerd, negative error code in case of
+     *         error.
+     */
+    int uuid_print(const wsrep::uuid_t* uuid, char* str, size_t str_len);
+}
+
+#endif // WSREP_UUID_HPP