---

yaml
---
r: 6627
b: refs/heads/master
c: 1ff8994
h: refs/heads/master
i:
  6625: 8943b53
  6623: ac6957c
v: v3

Author: nikomatsakis

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4b704ac69b17d8d338c25cdb24f8bcdfbd7565a4
+refs/heads/master: 1ff8994fce4a7ba719bc0b35dceb6442a66888a0

trunk/src/libstd/map.rs

@@ -353,211 +353,6 @@ mod chained {
     }
 }
 
-/*
-Function: mk_flat_hashmap
-
-Construct a "flat" hashmap, meaning that there are
-not chains per buckets, but rather we search a sequence
-of buckets for each key.
-
-Warning: it is unclear to me that this code is correct
-on 32-bit processors.  Check out the 'hash-tearing' code
-in hash() and the comment surrounding it. - Niko
-
-Parameters:
-
-hasher - The hash function for key type K
-eqer - The equality function for key type K
-*/
-fn mk_flat_hashmap<copy K, copy V>(hasher: hashfn<K>, eqer: eqfn<K>)
-    -> hashmap<K, V> {
-    let initial_capacity: uint = 32u; // 2^5
-
-    let load_factor: util::rational = {num: 3, den: 4};
-    tag bucket<copy K, copy V> { nil; deleted; some(K, V); }
-    fn make_buckets<copy K, copy V>(nbkts: uint) -> [mutable bucket<K, V>] {
-        ret vec::init_elt_mut::<bucket<K, V>>(nil::<K, V>, nbkts);
-    }
-    // Derive two hash functions from the one given by taking the upper
-    // half and lower half of the uint bits.  Our bucket probing
-    // sequence is then defined by
-    //
-    //   hash(key, i) := hashl(key) * i + hashr(key)   for i = 0, 1, 2, ...
-    //
-    // Tearing the hash function apart this way is kosher in practice
-    // as, assuming 32-bit uints, the table would have to be at 2^32
-    // buckets before the resulting pair of hash functions no longer
-    // probes all buckets for a fixed key.  Note that hashl is made to
-    // output odd numbers (hence coprime to the number of nbkts, which
-    // is always a power? of 2), so that all buckets are probed for a
-    // fixed key.
-
-    fn hashl(n: uint) -> uint { ret (n >>> 16u) * 2u + 1u; }
-    fn hashr(n: uint) -> uint { ret 0x0000_ffff_u & n; }
-    fn hash(h: uint, nbkts: uint, i: uint) -> uint {
-        ret (hashl(h) * i + hashr(h)) % nbkts;
-    }
-
-    /**
-     * We attempt to never call this with a full table.  If we do, it
-     * will fail.
-     */
-    fn insert_common<copy K, copy V>(hasher: hashfn<K>, eqer: eqfn<K>,
-                                     bkts: [mutable bucket<K, V>],
-                                     nbkts: uint, key: K, val: V) -> bool {
-        let i: uint = 0u;
-        let h = hasher(key);
-        while i < nbkts {
-            let j: uint = hash(h, nbkts, i);
-            alt bkts[j] {
-              some(k, _) {
-                // Copy key to please alias analysis.
-
-                let k_ = k;
-                if eqer(key, k_) {
-                    log("map updated", "i", i, "h", h, "nbkts", nbkts);
-                    bkts[j] = some(k_, val);
-                    ret false;
-                }
-                i += 1u;
-              }
-              _ {
-                log("map inserted", "i", i, "h", h, "nbkts", nbkts);
-                bkts[j] = some(key, val);
-                ret true;
-              }
-            }
-        }
-        fail; // full table
-    }
-    fn find_common<copy K, copy V>(hasher: hashfn<K>, eqer: eqfn<K>,
-                                   bkts: [mutable bucket<K, V>],
-                                   nbkts: uint, key: K) -> option::t<V> {
-        let i: uint = 0u;
-        let h = hasher(key);
-        while i < nbkts {
-            let j: uint = hash(h, nbkts, i);
-            alt bkts[j] {
-              some(k, v) {
-                // Copy to please alias analysis.
-                let k_ = k;
-                let v_ = v;
-                if eqer(key, k_) {
-                    log("map present", "i", i, "h", h, "nbkts", nbkts);
-                    ret option::some(v_);
-                }
-              }
-              nil. {
-                log("map absent", "i", i, "h", h, "nbkts", nbkts);
-                ret option::none;
-              }
-              deleted. { }
-            }
-            i += 1u;
-        }
-        ret option::none;
-    }
-    fn rehash<copy K, copy V>(hasher: hashfn<K>, eqer: eqfn<K>,
-                              oldbkts: [mutable bucket<K, V>],
-                              _noldbkts: uint,
-                              newbkts: [mutable bucket<K, V>],
-                              nnewbkts: uint) {
-        for b: bucket<K, V> in oldbkts {
-            alt b {
-              some(k_, v_) {
-                let k = k_;
-                let v = v_;
-                insert_common(hasher, eqer, newbkts, nnewbkts, k, v);
-              }
-              _ { }
-            }
-        }
-    }
-    obj hashmap<copy K, copy V>(hasher: hashfn<K>,
-                                eqer: eqfn<K>,
-                                mutable bkts: [mutable bucket<K, V>],
-                                mutable nbkts: uint,
-                                mutable nelts: uint,
-                                lf: util::rational) {
-        fn size() -> uint { ret nelts; }
-        fn insert(key: K, val: V) -> bool {
-            let load: util::rational =
-                {num: nelts + 1u as int, den: nbkts as int};
-            if !util::rational_leq(load, lf) {
-                let nnewbkts: uint = uint::next_power_of_two(nbkts + 1u);
-                let newbkts = make_buckets(nnewbkts);
-                rehash(hasher, eqer, bkts, nbkts, newbkts, nnewbkts);
-                bkts = newbkts;
-                nbkts = nnewbkts;
-            }
-            if insert_common(hasher, eqer, bkts, nbkts, key, val) {
-                nelts += 1u;
-                ret true;
-            }
-            ret false;
-        }
-        fn contains_key(key: K) -> bool {
-            ret alt find_common(hasher, eqer, bkts, nbkts, key) {
-                  option::some(_) { true }
-                  _ { false }
-                };
-        }
-        fn get(key: K) -> V {
-            ret alt find_common(hasher, eqer, bkts, nbkts, key) {
-                  option::some(val) { val }
-                  _ { fail }
-                };
-        }
-        fn find(key: K) -> option::t<V> {
-            be find_common(hasher, eqer, bkts, nbkts, key);
-        }
-        fn remove(key: K) -> option::t<V> {
-            let i: uint = 0u;
-            let h = hasher(key);
-            while i < nbkts {
-                let j: uint = hash(h, nbkts, i);
-                alt bkts[j] {
-                  some(k, v) {
-                    let k_ = k;
-                    let vo = option::some(v);
-                    if eqer(key, k_) {
-                        bkts[j] = deleted;
-                        nelts -= 1u;
-                        ret vo;
-                    }
-                  }
-                  deleted. { }
-                  nil. { ret option::none; }
-                }
-                i += 1u;
-            }
-            ret option::none;
-        }
-        fn rehash() {
-            let newbkts = make_buckets(nbkts);
-            rehash(hasher, eqer, bkts, nbkts, newbkts, nbkts);
-            bkts = newbkts;
-        }
-        fn items(it: block(K, V)) {
-            for b in bkts {
-                alt b { some(k, v) { it(copy k, copy v); } _ { } }
-            }
-        }
-        fn keys(it: block(K)) {
-            for b in bkts {
-                alt b { some(k, _) { it(copy k); } _ { } }
-            }
-        }
-        fn values(it: block(V)) {
-            for b in bkts {
-                alt b { some(_, v) { it(copy v); } _ { } }
-            }
-        }
-    }
-    let bkts = make_buckets(initial_capacity);
-    ret hashmap(hasher, eqer, bkts, initial_capacity, 0u, load_factor);
-}
-
 /*
 Function: mk_hashmap