lots of work on determinism in the linux driver.

luprex/core/cpp/util.cpp

@@ -269,22 +269,67 @@ double strtodouble(const std::string &value) {
     }
 }
 
-std::string ltrim(std::string s) {
-    s.erase(s.begin(), std::find_if(s.begin(), s.end(),
-            std::not1(std::ptr_fun<int, int>(std::isspace))));
-    return s;
+std::string_view sv_ltrim(std::string_view v) {
+    const char *b = v.data();
+    const char *e = v.data() + v.size();
+    while ((e > b) && (std::isspace(b[0]))) {
+        b++;
+    }
+    return std::string_view(b, e-b);
 }
 
-std::string rtrim(std::string s) {
-    s.erase(std::find_if(s.rbegin(), s.rend(),
-            std::not1(std::ptr_fun<int, int>(std::isspace))).base(), s.end());
-    return s;
+std::string_view sv_rtrim(std::string_view v) {
+    const char *b = v.data();
+    const char *e = v.data() + v.size();
+    while ((e > b) && (std::isspace(e[-1]))) {
+        e--;
+    }
+    return std::string_view(b, e-b);
 }
 
-std::string trim(std::string s) {
-    return ltrim(rtrim(s));
+std::string_view sv_trim(std::string_view v) {
+    const char *b = v.data();
+    const char *e = v.data() + v.size();
+    while ((e > b) && (std::isspace(b[0]))) {
+        b++;
+    }
+    while ((e > b) && (std::isspace(e[-1]))) {
+        e--;
+    }
+    return std::string_view(b, e-b);
 }
 
+std::string ltrim(std::string_view v) {
+    return std::string(sv_ltrim(v));
+}
+
+std::string rtrim(std::string_view v) {
+    return std::string(sv_rtrim(v));
+}
+
+std::string trim(std::string_view v) {
+    return std::string(sv_trim(v));
+}
+
+std::string_view sv_read_line(std::string_view &source) {
+    size_t pos = source.find('\n');
+    std::string_view result;
+    if (pos == std::string_view::npos) {
+        result = source;
+        source = "";
+    } else {
+        result = source.substr(0, pos);
+        source = source.substr(pos + 1);
+    }
+    int fsize = result.size();
+    if ((fsize >= 1) && (result[fsize - 1] == '\r')) {
+        result.remove_suffix(1);
+    }
+    return result;
+}
+
+
+
 double distance_squared(double x1, double y1, double x2, double y2) {
     double dx = x1 - x2;
     double dy = y1 - y2;
@@ -431,6 +476,15 @@ LuaDefine(unittests_util, "", "some unit tests") {
     LuaAssert(L, util::trim("foo") == "foo");
     LuaAssert(L, util::trim("") == "");
     
+    // Test sv_read_line
+    std::string_view v = "foo\nbar\r\n";
+    std::string_view v1 = util::sv_read_line(v);
+    std::string_view v2 = util::sv_read_line(v);
+    std::string_view v3 = util::sv_read_line(v);
+    LuaAssertStrEq(L, v1, "foo");
+    LuaAssertStrEq(L, v2, "bar");
+    LuaAssertStrEq(L, v3, "");
+
     // Test distance_squared
     LuaAssert(L, util::distance_squared(1, 1, 5, 4) == 25.0);
     LuaAssert(L, util::distance_squared(5, 4, 1, 1) == 25.0);