Move parse_range() and range_overlaps() into RangeSet.

Also move RangeSet into a header file to make it testable, and add unit
tests.

In RangeSet::Parse() (the former parse_range()), use libbase logging to
do assertions. This has the same effect as the previous
exit(EXIT_FAILURE) to terminate the updater process and abort an update.
The difference lies in the exit status code (i.e. WEXITSTATUS(status) in
install.cpp), which changes from 1 (i.e. EXIT_FAILURE) to 0.

Test: recovery_unit_test
Test: Apply an incremental update with the new updater.
Change-Id: Ie8393c78b0d8ae0fd5f0ca0646d871308d71fff0
diff --git a/tests/unit/rangeset_test.cpp b/tests/unit/rangeset_test.cpp
new file mode 100644
index 0000000..e66da20
--- /dev/null
+++ b/tests/unit/rangeset_test.cpp
@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <signal.h>
+#include <sys/types.h>
+
+#include <vector>
+
+#include <gtest/gtest.h>
+
+#include "updater/rangeset.h"
+
+TEST(RangeSetTest, Parse_smoke) {
+  RangeSet rs = RangeSet::Parse("2,1,10");
+  ASSERT_EQ(static_cast<size_t>(1), rs.count);
+  ASSERT_EQ((std::vector<size_t>{ 1, 10 }), rs.pos);
+  ASSERT_EQ(static_cast<size_t>(9), rs.size);
+
+  RangeSet rs2 = RangeSet::Parse("4,15,20,1,10");
+  ASSERT_EQ(static_cast<size_t>(2), rs2.count);
+  ASSERT_EQ((std::vector<size_t>{ 15, 20, 1, 10 }), rs2.pos);
+  ASSERT_EQ(static_cast<size_t>(14), rs2.size);
+
+  // Leading zeros are fine. But android::base::ParseUint() doesn't like trailing zeros like "10 ".
+  ASSERT_EQ(rs, RangeSet::Parse(" 2, 1,   10"));
+  ASSERT_EXIT(RangeSet::Parse("2,1,10 "), ::testing::KilledBySignal(SIGABRT), "");
+}
+
+TEST(RangeSetTest, Parse_InvalidCases) {
+  // Insufficient number of tokens.
+  ASSERT_EXIT(RangeSet::Parse(""), ::testing::KilledBySignal(SIGABRT), "");
+  ASSERT_EXIT(RangeSet::Parse("2,1"), ::testing::KilledBySignal(SIGABRT), "");
+
+  // The first token (i.e. the number of following tokens) is invalid.
+  ASSERT_EXIT(RangeSet::Parse("a,1,1"), ::testing::KilledBySignal(SIGABRT), "");
+  ASSERT_EXIT(RangeSet::Parse("3,1,1"), ::testing::KilledBySignal(SIGABRT), "");
+  ASSERT_EXIT(RangeSet::Parse("-3,1,1"), ::testing::KilledBySignal(SIGABRT), "");
+  ASSERT_EXIT(RangeSet::Parse("2,1,2,3"), ::testing::KilledBySignal(SIGABRT), "");
+
+  // Invalid tokens.
+  ASSERT_EXIT(RangeSet::Parse("2,1,10a"), ::testing::KilledBySignal(SIGABRT), "");
+  ASSERT_EXIT(RangeSet::Parse("2,,10"), ::testing::KilledBySignal(SIGABRT), "");
+
+  // Empty or negative range.
+  ASSERT_EXIT(RangeSet::Parse("2,2,2"), ::testing::KilledBySignal(SIGABRT), "");
+  ASSERT_EXIT(RangeSet::Parse("2,2,1"), ::testing::KilledBySignal(SIGABRT), "");
+}
+
+TEST(RangeSetTest, Overlaps) {
+  RangeSet r1 = RangeSet::Parse("2,1,6");
+  RangeSet r2 = RangeSet::Parse("2,5,10");
+  ASSERT_TRUE(r1.Overlaps(r2));
+  ASSERT_TRUE(r2.Overlaps(r1));
+
+  r2 = RangeSet::Parse("2,6,10");
+  ASSERT_FALSE(r1.Overlaps(r2));
+  ASSERT_FALSE(r2.Overlaps(r1));
+
+  ASSERT_FALSE(RangeSet::Parse("2,3,5").Overlaps(RangeSet::Parse("2,5,7")));
+  ASSERT_FALSE(RangeSet::Parse("2,5,7").Overlaps(RangeSet::Parse("2,3,5")));
+}
+
+TEST(RangeSetTest, GetBlockNumber) {
+  RangeSet rs = RangeSet::Parse("2,1,10");
+  ASSERT_EQ(static_cast<size_t>(1), rs.GetBlockNumber(0));
+  ASSERT_EQ(static_cast<size_t>(6), rs.GetBlockNumber(5));
+  ASSERT_EQ(static_cast<size_t>(9), rs.GetBlockNumber(8));
+
+  // Out of bound.
+  ASSERT_EXIT(rs.GetBlockNumber(9), ::testing::KilledBySignal(SIGABRT), "");
+}