Issue/389 (#405)

* Setting up the dependency.

* Completed README

11 files changed, 87 insertions, 27 deletions

diff --git a/Cargo.toml b/Cargo.toml
index ab767d3..098ab91 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -48,6 +48,7 @@ census = "0.1"
 fnv = "1.0.6"
 owned-read = "0.4"
 failure = "0.1"
+fail = "0.2"
 
 [target.'cfg(windows)'.dependencies]
 winapi = "0.2"
@@ -60,12 +61,20 @@ opt-level = 3
 debug = false
 lto = true
 debug-assertions = false
+overflow-checks = false
+
+[profile.test]
+debug-assertions = true
+overflow-checks = true
 
 [features]
-default = ["mmap"]
+# by default no-fail is disabled. We manually enable it when running test.
+default = ["mmap", "no_fail"]
 mmap = ["fst/mmap", "atomicwrites"]
 lz4-compression = ["lz4"]
+no_fail = ["fail/no_fail"]
 
 [badges]
 travis-ci = { repository = "tantivy-search/tantivy" }
 
+
diff --git a/README.md b/README.md
index 499a124..0ce522a 100644
--- a/README.md
+++ b/README.md
@@ -78,6 +78,10 @@ To check out and run tests, you can simply run :
     cd tantivy
     cargo build
 
+## Running tests
+
+Some tests will not run with just `cargo test` because of `fail-rs`.
+To run the tests exhaustively, run `./run-tests.sh`. 
 
 # Contribute
 
diff --git a/appveyor.yml b/appveyor.yml
index a3bd2ac..685b04d 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -18,5 +18,5 @@ install:
 build: false
 
 test_script:
-  - REM SET RUST_LOG=tantivy,test & cargo test --verbose
-  - REM SET RUST_BACKTRACE=1 & cargo build --examples
\ No newline at end of file
+  - REM SET RUST_LOG=tantivy,test & cargo test --verbose --no-default-features --features mmap -- --test-threads 1
+  - REM SET RUST_BACKTRACE=1 & cargo build --examples
diff --git a/ci/script.sh b/ci/script.sh
index b563457..0939344 100644
--- a/ci/script.sh
+++ b/ci/script.sh
@@ -16,7 +16,7 @@ main() {
             return
         fi
         echo "Test"
-        cross test --target $TARGET
+        cross test --target $TARGET --no-default-features --features mmap -- --test-threads 1
     fi
     for example in $(ls examples/*.rs)
     do
diff --git a/run-tests.sh b/run-tests.sh
new file mode 100755
index 0000000..fc2944d
--- /dev/null
+++ b/run-tests.sh
@@ -0,0 +1,2 @@
+#!/bin/bash
+cargo test --no-default-features --features mmap -- --test-threads 1
diff --git a/src/common/bitset.rs b/src/common/bitset.rs
index 73f03c4..326e7ce 100644
--- a/src/common/bitset.rs
+++ b/src/common/bitset.rs
@@ -266,14 +266,14 @@ mod tests {
 
     #[test]
     fn test_bitset_large() {
-        let arr = generate_nonunique_unsorted(1_000_000, 50_000);
+        let arr = generate_nonunique_unsorted(100_000, 5_000);
         let mut btreeset: BTreeSet<u32> = BTreeSet::new();
-        let mut bitset = BitSet::with_max_value(1_000_000);
+        let mut bitset = BitSet::with_max_value(100_000);
         for el in arr {
             btreeset.insert(el);
             bitset.insert(el);
         }
-        for i in 0..1_000_000 {
+        for i in 0..100_000 {
             assert_eq!(btreeset.contains(&i), bitset.contains(i));
         }
         assert_eq!(btreeset.len(), bitset.len());
diff --git a/src/core/segment_reader.rs b/src/core/segment_reader.rs
index 37b9503..517e153 100644
--- a/src/core/segment_reader.rs
+++ b/src/core/segment_reader.rs
@@ -225,6 +225,8 @@ impl SegmentReader {
         let store_source = segment.open_read(SegmentComponent::STORE)?;
         let store_reader = StoreReader::from_source(store_source);
 
+        fail_point!("SegmentReader::open#middle");
+
         let postings_source = segment.open_read(SegmentComponent::POSTINGS)?;
         let postings_composite = CompositeFile::open(&postings_source)?;
 
@@ -432,6 +434,7 @@ mod test {
     use schema::{SchemaBuilder, Term, STORED, TEXT};
     use DocId;
 
+
     #[test]
     fn test_alive_docs_iterator() {
         let mut schema_builder = SchemaBuilder::new();
diff --git a/src/directory/ram_directory.rs b/src/directory/ram_directory.rs
index 4e55da5..1b40970 100644
--- a/src/directory/ram_directory.rs
+++ b/src/directory/ram_directory.rs
@@ -195,6 +195,9 @@ impl Directory for RAMDirectory {
     }
 
     fn atomic_write(&mut self, path: &Path, data: &[u8]) -> io::Result<()> {
+        fail_point!("RAMDirectory::atomic_write", |msg| {
+            Err(io::Error::new(io::ErrorKind::Other, msg.unwrap_or("Undefined".to_string())))
+        });
         let path_buf = PathBuf::from(path);
         let mut vec_writer = VecWriter::new(path_buf.clone(), self.fs.clone());
         self.fs.write(path_buf, &Vec::new())?;
diff --git a/src/fastfield/mod.rs b/src/fastfield/mod.rs
index e3599ba..fdb0294 100644
--- a/src/fastfield/mod.rs
+++ b/src/fastfield/mod.rs
@@ -370,7 +370,7 @@ mod tests {
     pub fn generate_permutation() -> Vec<u64> {
         let seed: [u8; 16] = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16];
         let mut rng = XorShiftRng::from_seed(seed);
-        let mut permutation: Vec<u64> = (0u64..1_000_000u64).collect();
+        let mut permutation: Vec<u64> = (0u64..100_000u64).collect();
         rng.shuffle(&mut permutation);
         permutation
     }
diff --git a/src/indexer/index_writer.rs b/src/indexer/index_writer.rs
index 5af4ed6..3e11c4c 100644
--- a/src/indexer/index_writer.rs
+++ b/src/indexer/index_writer.rs
@@ -301,25 +301,31 @@ fn index_documents(
 
     let last_docstamp: u64 = *(doc_opstamps.last().unwrap());
 
-    let doc_to_opstamps = DocToOpstampMapping::from(doc_opstamps);
-    let segment_reader = SegmentReader::open(segment)?;
-    let mut deleted_bitset = BitSet::with_capacity(num_docs as usize);
-    let may_have_deletes = compute_deleted_bitset(
-        &mut deleted_bitset,
-        &segment_reader,
-        &mut delete_cursor,
-        &doc_to_opstamps,
-        last_docstamp,
-    )?;
-
-    let segment_entry = SegmentEntry::new(segment_meta, delete_cursor, {
-        if may_have_deletes {
-            Some(deleted_bitset)
-        } else {
-            None
-        }
-    });
-
+    let segment_entry: SegmentEntry;
+
+    if delete_cursor.get().is_some() {
+        let doc_to_opstamps = DocToOpstampMapping::from(doc_opstamps);
+        let segment_reader = SegmentReader::open(segment)?;
+        let mut deleted_bitset = BitSet::with_capacity(num_docs as usize);
+        let may_have_deletes = compute_deleted_bitset(
+            &mut deleted_bitset,
+            &segment_reader,
+            &mut delete_cursor,
+            &doc_to_opstamps,
+            last_docstamp,
+        )?;
+        segment_entry = SegmentEntry::new(segment_meta, delete_cursor, {
+            if may_have_deletes {
+                Some(deleted_bitset)
+            } else {
+                None
+            }
+        });
+    } else {
+        // if there are no delete operation in the queue, no need
+        // to even open the segment.
+        segment_entry = SegmentEntry::new(segment_meta, delete_cursor, None);
+    }
     Ok(segment_updater.add_segment(generation, segment_entry))
 }
 
@@ -858,4 +864,33 @@ mod tests {
         assert_eq!(initial_table_size(1_000_000_000), 19);
     }
 
+
+    #[cfg(not(feature="no_fail"))]
+    #[test]
+    fn test_write_commit_fails() {
+        use fail;
+        let mut schema_builder = schema::SchemaBuilder::default();
+        let text_field = schema_builder.add_text_field("text", schema::TEXT);
+        let index = Index::create_in_ram(schema_builder.build());
+
+        let mut index_writer = index.writer_with_num_threads(1, 3_000_000).unwrap();
+        for _    in 0..100 {
+            index_writer.add_document(doc!(text_field => "a"));
+        }
+        index_writer.commit().unwrap();
+        fail::cfg("RAMDirectory::atomic_write", "return(error_write_failed)").unwrap();
+        for _ in 0..100 {
+            index_writer.add_document(doc!(text_field => "b"));
+        }
+        assert!(index_writer.commit().is_err());
+        index.load_searchers().unwrap();
+        let num_docs_containing = |s: &str| {
+            let searcher = index.searcher();
+            let term_a = Term::from_field_text(text_field, s);
+            searcher.doc_freq(&term_a)
+        };
+        assert_eq!(num_docs_containing("a"), 100);
+        assert_eq!(num_docs_containing("b"), 0);
+        fail::cfg("RAMDirectory::atomic_write", "off").unwrap();
+    }
 }
diff --git a/src/lib.rs b/src/lib.rs
index 985d68a..e5a75cd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -173,6 +173,9 @@ extern crate tinysegmenter;
 #[macro_use]
 extern crate downcast;
 
+#[macro_use]
+extern crate fail;
+
 #[cfg(test)]
 mod functional_test;
 
@@ -946,3 +949,4 @@ mod tests {
         }
     }
 }
+