rewrite metadata indexing

this improves the compilation time for small crates by ~20%

Author: Ariel Ben-Yehuda

src/librustc/lib.rs

@@ -51,7 +51,6 @@
 #![feature(rustc_diagnostic_macros)]
 #![feature(rustc_private)]
 #![feature(scoped_tls)]
-#![feature(slice_bytes)]
 #![feature(slice_splits)]
 #![feature(slice_patterns)]
 #![feature(staged_api)]

src/librustc/metadata/common.rs

@@ -45,13 +45,7 @@ pub const tag_items_data_item_is_tuple_struct_ctor: usize = 0x29;
 
 pub const tag_index: usize = 0x2a;
 
-pub const tag_index_buckets: usize = 0x2b;
-
-pub const tag_index_buckets_bucket: usize = 0x2c;
-
-pub const tag_index_buckets_bucket_elt: usize = 0x2d;
-
-pub const tag_index_table: usize = 0x2e;
+// GAP 0x2b, 0x2c, 0x2d, 0x2e
 
 pub const tag_meta_item_name_value: usize = 0x2f;
 

src/librustc/metadata/creader.rs

@@ -304,6 +304,7 @@ impl<'a> CrateReader<'a> {
         let cmeta = Rc::new(cstore::crate_metadata {
             name: name.to_string(),
             local_path: RefCell::new(SmallVector::zero()),
+            index: decoder::load_index(metadata.as_slice()),
             data: metadata,
             cnum_map: RefCell::new(cnum_map),
             cnum: cnum,
@@ -521,7 +522,7 @@ impl<'a> CrateReader<'a> {
         }
 
         let registrar = decoder::get_plugin_registrar_fn(ekrate.metadata.as_slice())
-            .map(|id| decoder::get_symbol(ekrate.metadata.as_slice(), id));
+            .map(|id| decoder::get_symbol_from_buf(ekrate.metadata.as_slice(), id));
 
         match (ekrate.dylib.as_ref(), registrar) {
             (Some(dylib), Some(reg)) => Some((dylib.to_path_buf(), reg)),

src/librustc/metadata/csearch.rs

@@ -11,23 +11,18 @@
 // Searching for information from the cstore
 
 use front::map as ast_map;
-use metadata::common::*;
 use metadata::cstore;
 use metadata::decoder;
 use metadata::inline::InlinedItem;
 use middle::def_id::DefId;
 use middle::lang_items;
 use middle::ty;
+use util::nodemap::FnvHashMap;
 
-use rbml;
-use rbml::reader;
 use std::rc::Rc;
 use syntax::ast;
 use rustc_front::attr;
 use rustc_front::hir;
-use syntax::diagnostic::expect;
-
-use std::collections::hash_map::HashMap;
 
 #[derive(Copy, Clone)]
 pub struct MethodInfo {
@@ -38,7 +33,7 @@ pub struct MethodInfo {
 
 pub fn get_symbol(cstore: &cstore::CStore, def: DefId) -> String {
     let cdata = cstore.get_crate_data(def.krate);
-    decoder::get_symbol(cdata.data(), def.node)
+    decoder::get_symbol(&cdata, def.node)
 }
 
 /// Iterates over all the language items in the given crate.
@@ -201,7 +196,7 @@ pub fn get_struct_field_names(cstore: &cstore::CStore, def: DefId) -> Vec<ast::N
     decoder::get_struct_field_names(&cstore.intr, &*cdata, def.node)
 }
 
-pub fn get_struct_field_attrs(cstore: &cstore::CStore, def: DefId) -> HashMap<ast::NodeId,
+pub fn get_struct_field_attrs(cstore: &cstore::CStore, def: DefId) -> FnvHashMap<ast::NodeId,
         Vec<hir::Attribute>> {
     let cdata = cstore.get_crate_data(def.krate);
     decoder::get_struct_field_attrs(&*cdata)
@@ -243,31 +238,6 @@ pub fn get_super_predicates<'tcx>(tcx: &ty::ctxt<'tcx>, def: DefId)
     decoder::get_super_predicates(&*cdata, def.node, tcx)
 }
 
-pub fn get_field_type<'tcx>(tcx: &ty::ctxt<'tcx>, class_id: DefId,
-                            def: DefId) -> ty::TypeScheme<'tcx> {
-    let cstore = &tcx.sess.cstore;
-    let cdata = cstore.get_crate_data(class_id.krate);
-    let all_items = reader::get_doc(rbml::Doc::new(cdata.data()), tag_items);
-    let class_doc = expect(tcx.sess.diagnostic(),
-                           decoder::maybe_find_item(class_id.node, all_items),
-                           || {
-        (format!("get_field_type: class ID {:?} not found",
-                 class_id)).to_string()
-    });
-    let the_field = expect(tcx.sess.diagnostic(),
-        decoder::maybe_find_item(def.node, class_doc),
-        || {
-            (format!("get_field_type: in class {:?}, field ID {:?} not found",
-                    class_id,
-                    def)).to_string()
-        });
-    let ty = decoder::item_type(def, the_field, tcx, &*cdata);
-    ty::TypeScheme {
-        generics: ty::Generics::empty(),
-        ty: ty,
-    }
-}
-
 pub fn get_impl_polarity<'tcx>(tcx: &ty::ctxt<'tcx>,
                                def: DefId)
                                -> Option<hir::ImplPolarity>

src/librustc/metadata/cstore.rs

@@ -18,7 +18,7 @@ pub use self::LinkagePreference::*;
 pub use self::NativeLibraryKind::*;
 
 use back::svh::Svh;
-use metadata::{creader, decoder, loader};
+use metadata::{creader, decoder, index, loader};
 use session::search_paths::PathKind;
 use util::nodemap::{FnvHashMap, NodeMap, NodeSet};
 
@@ -65,6 +65,7 @@ pub struct crate_metadata {
     pub codemap_import_info: RefCell<Vec<ImportedFileMap>>,
     pub span: codemap::Span,
     pub staged_api: bool,
+    pub index: index::Index,
 
     /// Flag if this crate is required by an rlib version of this crate, or in
     /// other words whether it was explicitly linked to. An example of a crate