[2148] cleanup and documentation

src/lib/dns/labelsequence.cc

@@ -345,7 +345,7 @@ LabelSequence::extend(const LabelSequence& labels,
     bool absolute = isAbsolute();
     size_t label_count = last_label_ + 1;
     // Since we may have been stripped, do not use getDataLength(), but
-    // calculate actual data size we use
+    // calculate actual data size this labelsequence currently uses
     size_t data_pos = offsets_[last_label_] + data_[offsets_[last_label_]] + 1;
 
     // If this labelsequence is absolute, virtually strip the root label.
@@ -378,7 +378,7 @@ LabelSequence::extend(const LabelSequence& labels,
     // case we'd be copying overlapping data (overwriting the current last
     // label if this LabelSequence is absolute). Therefore we do this
     // manually, and more importantly, backwards.
-    // (note2 obviously this destroys data_len, don't use below,
+    // (note2: obviously this destroys data_len, don't use below,
     // or reset it)
     while (--data_len) {
         buf[data_pos + data_len] = data[data_len];
@@ -387,9 +387,9 @@ LabelSequence::extend(const LabelSequence& labels,
 
     for (size_t i = 0; i < append_label_count; ++i) {
         buf[Name::MAX_WIRE + label_count + i] =
-                                  offsets_[label_count] +
-                                  labels.offsets_[i + labels.first_label_] -
-                                  labels.offsets_[labels.first_label_];
+            offsets_[label_count] +
+            labels.offsets_[i + labels.first_label_] -
+            labels.offsets_[labels.first_label_];
     }
     last_label_ = label_count + append_label_count - 1;
 }
@@ -400,30 +400,5 @@ operator<<(std::ostream& os, const LabelSequence& label_sequence) {
     return (os);
 }
 
-void
-LabelSequence::dump() const {
-    std::cout << "[XX] serialized data: ";
-    for (size_t i = 0; i < getDataLength(); ++i) {
-        std::cout << (int)data_[i] << " ";
-    }
-    std::cout << std::endl;
-    std::cout << "[XX] offsets: ";
-    size_t cur_offset = 0;
-    uint8_t cur_ll = data_[offsets_[cur_offset]];
-    while(cur_ll != 0) {
-        std::cout << (int)offsets_[cur_offset] << " ";
-        cur_offset++;
-        cur_ll = data_[offsets_[cur_offset]];
-    }
-    std::cout << std::endl;
-    std::cout << "[XX] first label: " << first_label_ << std::endl;
-    std::cout << "[XX] last label: " << last_label_ << std::endl;
-    if (isAbsolute()) {
-        std::cout << "[XX] absolute" << std::endl;
-    } else {
-        std::cout << "[XX] not absolute" << std::endl;
-    }
-}
-
 } // end namespace dns
 } // end namespace isc

src/lib/dns/labelsequence.h

@@ -268,12 +268,20 @@ public:
 
     /// \brief Extend this LabelSequence with the given labelsequence
     ///
-    /// The given labels are added to the name data, and internal data
-    /// is updated accordingly.
+    /// The given labels are added to the name data, and internal offset
+    /// data is updated accordingly.
+    ///
     /// The data from the given LabelSequence is copied into the buffer
     /// associated with this LabelSequence; the appended LabelSequence
     /// can be released if it is not needed for other operations anymore.
     ///
+    /// If this LabelSequence is absolute, its root label will be stripped
+    /// before the given LabelSequence is appended; after extend(),
+    /// this LabelSequence will be absolute if, and only if, the appended
+    /// LabelSequence was. A side-effect of this property is that adding
+    /// the root label to an absolute LabelSequence has no effect (the
+    /// root label is stripped, then added again).
+    ///
     /// Some minimal checking is done on the data, but internal integrity
     /// is not assumed. Do NOT modify the given buffer except through calls
     /// to this method, and do NOT call this method if the buffer is

src/lib/dns/tests/labelsequence_unittest.cc

@@ -1053,17 +1053,15 @@ TEST(LabelSequence, extendBadData) {
     els.extend(LabelSequence(Name("123456789")), buf);
     // But now, even the shortest extension should fail
     EXPECT_THROW(els.extend(LabelSequence(Name("1")), buf), isc::BadValue);
-/*
 
     // Also check that extending past MAX_LABELS is not possible
     Name shortname("1.");
     LabelSequence short_ls(shortname);
     els = LabelSequence(short_ls, buf);
-    for (size_t i=0; i < 125; ++i) {
+    for (size_t i=0; i < 126; ++i) {
         els.extend(short_ls, buf);
     }
     EXPECT_THROW(els.extend(short_ls, buf), isc::BadValue);
-*/
 }
 
 }