Refactor a few things in the metadata module

Rename metadata::tags to metadata::common. Move some utility functions from
metadata::encoder to metadata::common.

src/comp/metadata/common.rs

@@ -1,4 +1,6 @@
-// EBML tag definitions shared by the encoder and decoder
+// EBML tag definitions and utils shared by the encoder and decoder
+
+import std::str;
 
 const uint tag_paths = 0x01u;
 
@@ -52,4 +54,14 @@ const uint tag_attribute = 0x22u;
 
 const uint tag_meta_item_word = 0x23u;
 
-const uint tag_meta_item_list = 0x24u;
+const uint tag_meta_item_list = 0x24u;
+
+// djb's cdb hashes.
+fn hash_node_id(&int node_id) -> uint { ret 177573u ^ (node_id as uint); }
+
+fn hash_path(&str s) -> uint {
+    auto h = 5381u;
+    for (u8 ch in str::bytes(s)) { h = (h << 5u) + h ^ (ch as uint); }
+    ret h;
+}
+

src/comp/metadata/creader.rs

@@ -23,7 +23,7 @@ import std::option::none;
 import std::option::some;
 import std::map::hashmap;
 import syntax::print::pprust;
-import tags::*;
+import common::*;
 
 export read_crates;
 export list_file_metadata;

src/comp/metadata/decoder.rs

@@ -10,11 +10,10 @@ import std::map::hashmap;
 import syntax::ast;
 import front::attr;
 import middle::ty;
-import tags::*;
+import common::*;
 import tydecode::parse_def_id;
 import tydecode::parse_ty_data;
 import driver::session;
-import util::common;
 import syntax::print::pprust;
 
 export get_symbol;
@@ -51,7 +50,7 @@ fn maybe_find_item(int item_id, &ebml::doc items) -> option::t[ebml::doc] {
         ret ebml::be_uint_from_bytes(bytes, 0u, 4u) as int == item_id;
     }
     auto eqer = bind eq_item(_, item_id);
-    auto found = lookup_hash(items, eqer, encoder::hash_node_id(item_id));
+    auto found = lookup_hash(items, eqer, hash_node_id(item_id));
     if (vec::len(found) == 0u) {
         ret option::none[ebml::doc];
     } else { ret option::some[ebml::doc](found.(0)); }
@@ -129,7 +128,7 @@ fn resolve_path(vec[ast::ident] path, vec[u8] data) -> vec[ast::def_id] {
     auto paths = ebml::get_doc(md, tag_paths);
     auto eqer = bind eq_item(_, s);
     let vec[ast::def_id] result = [];
-    for (ebml::doc doc in lookup_hash(paths, eqer, encoder::hash_path(s))) {
+    for (ebml::doc doc in lookup_hash(paths, eqer, hash_path(s))) {
         auto did_doc = ebml::get_doc(doc, tag_def_id);
         vec::push(result, parse_def_id(ebml::doc_data(did_doc)));
     }

src/comp/metadata/encoder.rs

@@ -10,15 +10,13 @@ import std::option::some;
 import std::option::none;
 import std::ebml;
 import syntax::ast::*;
-import tags::*;
+import common::*;
 import middle::trans::crate_ctxt;
 import middle::ty;
 import middle::ty::node_id_to_monotype;
 import front::attr;
 
 export def_to_str;
-export hash_path;
-export hash_node_id;
 export encode_metadata;
 
 // Path table encoding
@@ -370,15 +368,6 @@ fn encode_info_for_items(&@crate_ctxt cx, &ebml::writer ebml_w) ->
 
 // Path and definition ID indexing
 
-// djb's cdb hashes.
-fn hash_node_id(&int node_id) -> uint { ret 177573u ^ (node_id as uint); }
-
-fn hash_path(&str s) -> uint {
-    auto h = 5381u;
-    for (u8 ch in str::bytes(s)) { h = (h << 5u) + h ^ (ch as uint); }
-    ret h;
-}
-
 fn create_index[T](&vec[tup(T, uint)] index, fn(&T) -> uint  hash_fn) ->
    vec[vec[tup(T, uint)]] {
     let vec[mutable vec[tup(T, uint)]] buckets = vec::empty_mut();

src/comp/rustc.rc

@@ -82,7 +82,7 @@ mod metadata {
     export decoder;
     export creader;
 
-    mod tags;
+    mod common;
     mod tyencode;
     mod tydecode;
     mod encoder;