[cache_check (rust)] Add more checks

- Report errors
- Support reading partially broken bitset
  - The output is a bitmap of 2-bit entries, indicating availability of bits

src/bin/cache_check.rs

@@ -1,8 +1,12 @@
 extern crate clap;
 extern crate thinp;
 
+use atty::Stream;
 use clap::{App, Arg};
 use std::path::Path;
+use std::sync::Arc;
+
+use thinp::report::*;
 use thinp::cache::check::{check, CacheCheckOptions};
 
 //------------------------------------------
@@ -39,11 +43,26 @@ fn main() {
                 .help("Don't check the discard bitset")
                 .long("skip-discards")
                 .value_name("SKIP_DISCARDS"),
+        )
+        .arg(
+            Arg::with_name("QUIET")
+                .help("Suppress output messages, return only exit code.")
+                .short("q")
+                .long("quiet"),
         );
 
     let matches = parser.get_matches();
     let input_file = Path::new(matches.value_of("INPUT").unwrap());
 
+    let report;
+    if matches.is_present("QUIET") {
+        report = std::sync::Arc::new(mk_quiet_report());
+    } else if atty::is(Stream::Stdout) {
+        report = std::sync::Arc::new(mk_progress_bar_report());
+    } else {
+        report = Arc::new(mk_simple_report());
+    }
+
     let opts = CacheCheckOptions {
         dev: &input_file,
         async_io: false,
@@ -51,6 +70,7 @@ fn main() {
         skip_mappings: matches.is_present("SKIP_MAPPINGS"),
         skip_hints: matches.is_present("SKIP_HINTS"),
         skip_discards: matches.is_present("SKIP_DISCARDS"),
+        report,
     };
 
     if let Err(reason) = check(opts) {