1 // Copyright 2011 Google Inc. All Rights Reserved.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //     http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 
15 #ifndef NINJA_STATE_H_
16 #define NINJA_STATE_H_
17 
18 #include <map>
19 #include <set>
20 #include <string>
21 #include <vector>
22 using namespace std;
23 
24 #include "eval_env.h"
25 #include "hash_map.h"
26 #include "util.h"
27 
28 struct Edge;
29 struct Node;
30 struct Rule;
31 
32 /// A pool for delayed edges.
33 /// Pools are scoped to a State. Edges within a State will share Pools. A Pool
34 /// will keep a count of the total 'weight' of the currently scheduled edges. If
35 /// a Plan attempts to schedule an Edge which would cause the total weight to
36 /// exceed the depth of the Pool, the Pool will enque the Edge instead of
37 /// allowing the Plan to schedule it. The Pool will relinquish queued Edges when
38 /// the total scheduled weight diminishes enough (i.e. when a scheduled edge
39 /// completes).
40 struct Pool {
PoolPool41   Pool(const string& name, int depth)
42     : name_(name), current_use_(0), depth_(depth), delayed_(&WeightedEdgeCmp) {}
43 
44   // A depth of 0 is infinite
is_validPool45   bool is_valid() const { return depth_ >= 0; }
depthPool46   int depth() const { return depth_; }
namePool47   const string& name() const { return name_; }
current_usePool48   int current_use() const { return current_use_; }
49 
50   /// true if the Pool might delay this edge
ShouldDelayEdgePool51   bool ShouldDelayEdge() const { return depth_ != 0; }
52 
53   /// informs this Pool that the given edge is committed to be run.
54   /// Pool will count this edge as using resources from this pool.
55   void EdgeScheduled(const Edge& edge);
56 
57   /// informs this Pool that the given edge is no longer runnable, and should
58   /// relinquish its resources back to the pool
59   void EdgeFinished(const Edge& edge);
60 
61   /// adds the given edge to this Pool to be delayed.
62   void DelayEdge(Edge* edge);
63 
64   /// Pool will add zero or more edges to the ready_queue
65   void RetrieveReadyEdges(set<Edge*>* ready_queue);
66 
67   /// Dump the Pool and its edges (useful for debugging).
68   void Dump() const;
69 
70  private:
71   string name_;
72 
73   /// |current_use_| is the total of the weights of the edges which are
74   /// currently scheduled in the Plan (i.e. the edges in Plan::ready_).
75   int current_use_;
76   int depth_;
77 
78   static bool WeightedEdgeCmp(const Edge* a, const Edge* b);
79 
80   typedef set<Edge*,bool(*)(const Edge*, const Edge*)> DelayedEdges;
81   DelayedEdges delayed_;
82 };
83 
84 /// Global state (file status) for a single run.
85 struct State {
86   static Pool kDefaultPool;
87   static Pool kConsolePool;
88   static const Rule kPhonyRule;
89 
90   State();
91 
92   void AddPool(Pool* pool);
93   Pool* LookupPool(const string& pool_name);
94 
95   Edge* AddEdge(const Rule* rule);
96 
97   Node* GetNode(StringPiece path, uint64_t slash_bits);
98   Node* LookupNode(StringPiece path) const;
99   Node* SpellcheckNode(const string& path);
100 
101   void AddIn(Edge* edge, StringPiece path, uint64_t slash_bits);
102   bool AddOut(Edge* edge, StringPiece path, uint64_t slash_bits);
103   bool AddDefault(StringPiece path, string* error);
104 
105   /// Reset state.  Keeps all nodes and edges, but restores them to the
106   /// state where we haven't yet examined the disk for dirty state.
107   void Reset();
108 
109   /// Dump the nodes and Pools (useful for debugging).
110   void Dump();
111 
112   /// @return the root node(s) of the graph. (Root nodes have no output edges).
113   /// @param error where to write the error message if somethings went wrong.
114   vector<Node*> RootNodes(string* error) const;
115   vector<Node*> DefaultNodes(string* error) const;
116 
117   /// Mapping of path -> Node.
118   typedef ExternalStringHashMap<Node*>::Type Paths;
119   Paths paths_;
120 
121   /// All the pools used in the graph.
122   map<string, Pool*> pools_;
123 
124   /// All the edges of the graph.
125   vector<Edge*> edges_;
126 
127   BindingEnv bindings_;
128   vector<Node*> defaults_;
129 };
130 
131 #endif  // NINJA_STATE_H_
132