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+/**
+ * @file lldependencies.h
+ * @author Nat Goodspeed
+ * @date 2008-09-17
+ * @brief LLDependencies: a generic mechanism for expressing "b must follow a,
+ * but precede c"
+ *
+ * $LicenseInfo:firstyear=2008&license=viewergpl$
+ * Copyright (c) 2008, Linden Research, Inc.
+ * $/LicenseInfo$
+ */
+
+#if ! defined(LL_LLDEPENDENCIES_H)
+#define LL_LLDEPENDENCIES_H
+
+#include <string>
+#include <vector>
+#include <set>
+#include <map>
+#include <stdexcept>
+#include <iosfwd>
+#include <boost/iterator/transform_iterator.hpp>
+#include <boost/iterator/indirect_iterator.hpp>
+#include <boost/range/iterator_range.hpp>
+#include <boost/function.hpp>
+#include <boost/bind.hpp>
+
+/*****************************************************************************
+* Utilities
+*****************************************************************************/
+/**
+ * generic range transformer: given a range acceptable to Boost.Range (e.g. a
+ * standard container, an iterator pair, ...) and a unary function to apply to
+ * each element of the range, make a corresponding range that lazily applies
+ * that function to each element on dereferencing.
+ */
+template<typename FUNCTION, typename RANGE>
+inline
+boost::iterator_range<boost::transform_iterator<FUNCTION,
+ typename boost::range_const_iterator<RANGE>::type> >
+make_transform_range(const RANGE& range, FUNCTION function)
+{
+ // shorthand for the iterator type embedded in our return type
+ typedef boost::transform_iterator<FUNCTION, typename boost::range_const_iterator<RANGE>::type>
+ transform_iterator;
+ return boost::make_iterator_range(transform_iterator(boost::begin(range), function),
+ transform_iterator(boost::end(range), function));
+}
+
+/// non-const version of make_transform_range()
+template<typename FUNCTION, typename RANGE>
+inline
+boost::iterator_range<boost::transform_iterator<FUNCTION,
+ typename boost::range_iterator<RANGE>::type> >
+make_transform_range(RANGE& range, FUNCTION function)
+{
+ // shorthand for the iterator type embedded in our return type
+ typedef boost::transform_iterator<FUNCTION, typename boost::range_iterator<RANGE>::type>
+ transform_iterator;
+ return boost::make_iterator_range(transform_iterator(boost::begin(range), function),
+ transform_iterator(boost::end(range), function));
+}
+
+/**
+ * From any range compatible with Boost.Range, instantiate any class capable
+ * of accepting an iterator pair.
+ */
+template<class TYPE>
+struct instance_from_range: public TYPE
+{
+ template<typename RANGE>
+ instance_from_range(RANGE range):
+ TYPE(boost::begin(range), boost::end(range))
+ {}
+};
+
+/*****************************************************************************
+* LLDependencies
+*****************************************************************************/
+/**
+ * LLDependencies components that should not be reinstantiated for each KEY,
+ * NODE specialization
+ */
+class LLDependenciesBase
+{
+public:
+ virtual ~LLDependenciesBase() {}
+
+ /**
+ * Exception thrown by sort() if there's a cycle
+ */
+ struct Cycle: public std::runtime_error
+ {
+ Cycle(const std::string& what): std::runtime_error(what) {}
+ };
+
+ /**
+ * Provide a short description of this LLDependencies instance on the
+ * specified output stream, assuming that its KEY type has an operator<<()
+ * that works with std::ostream.
+ *
+ * Pass @a full as @c false to omit any keys without dependency constraints.
+ */
+ virtual std::ostream& describe(std::ostream& out, bool full=true) const;
+
+ /// describe() to a string
+ virtual std::string describe(bool full=true) const;
+
+protected:
+ typedef std::vector< std::pair<int, int> > EdgeList;
+ typedef std::vector<int> VertexList;
+ VertexList topo_sort(int vertices, const EdgeList& edges) const;
+
+ /**
+ * refpair is specifically intended to capture a pair of references. This
+ * is better than std::pair<T1&, T2&> because some implementations of
+ * std::pair's ctor accept const references to the two types. If the
+ * types are themselves references, this results in an illegal reference-
+ * to-reference.
+ */
+ template<typename T1, typename T2>
+ struct refpair
+ {
+ refpair(T1 value1, T2 value2):
+ first(value1),
+ second(value2)
+ {}
+ T1 first;
+ T2 second;
+ };
+};
+
+/// describe() helper: for most types, report the type as usual
+template<typename T>
+inline
+std::ostream& LLDependencies_describe(std::ostream& out, const T& key)
+{
+ out << key;
+ return out;
+}
+
+/// specialize LLDependencies_describe() for std::string
+template<>
+inline
+std::ostream& LLDependencies_describe(std::ostream& out, const std::string& key)
+{
+ out << '"' << key << '"';
+ return out;
+}
+
+/**
+ * It's reasonable to use LLDependencies in a keys-only way, more or less like
+ * std::set. For that case, the default NODE type is an empty struct.
+ */
+struct LLDependenciesEmpty
+{
+ LLDependenciesEmpty() {}
+ /**
+ * Give it a constructor accepting void* so caller can pass placeholder
+ * values such as NULL or 0 rather than having to write
+ * LLDependenciesEmpty().
+ */
+ LLDependenciesEmpty(void*) {}
+};
+
+/**
+ * This class manages abstract dependencies between node types of your
+ * choosing. As with a std::map, nodes are copied when add()ed, so the node
+ * type should be relatively lightweight; to manipulate dependencies between
+ * expensive objects, use a pointer type.
+ *
+ * For a given node, you may state the keys of nodes that must precede it
+ * and/or nodes that must follow it. The sort() method will produce an order
+ * that should work, or throw an exception if the constraints are impossible.
+ * We cache results to minimize the cost of repeated sort() calls.
+ */
+template<typename KEY = std::string,
+ typename NODE = LLDependenciesEmpty>
+class LLDependencies: public LLDependenciesBase
+{
+ typedef LLDependencies<KEY, NODE> self_type;
+
+ /**
+ * Internally, we bundle the client's NODE with its before/after keys.
+ */
+ struct DepNode
+ {
+ typedef std::set<KEY> dep_set;
+ DepNode(const NODE& node_, const dep_set& after_, const dep_set& before_):
+ node(node_),
+ after(after_),
+ before(before_)
+ {}
+ NODE node;
+ dep_set after, before;
+ };
+ typedef std::map<KEY, DepNode> DepNodeMap;
+ typedef typename DepNodeMap::value_type DepNodeMapEntry;
+
+ /// We have various ways to get the dependencies for a given DepNode.
+ /// Rather than having to restate each one for 'after' and 'before'
+ /// separately, pass a dep_selector so we can apply each to either.
+ typedef boost::function<const typename DepNode::dep_set&(const DepNode&)> dep_selector;
+
+public:
+ LLDependencies() {}
+
+ typedef KEY key_type;
+ typedef NODE node_type;
+
+ /// param type used to express lists of other node keys -- note that such
+ /// lists can be initialized with boost::assign::list_of()
+ typedef std::vector<KEY> KeyList;
+
+ /**
+ * Add a new node. State its dependencies on other nodes (which may not
+ * yet have been added) by listing the keys of nodes this new one must
+ * follow, and separately the keys of nodes this new one must precede.
+ *
+ * The node you pass is @em copied into an internal data structure. If you
+ * want to modify the node value after add()ing it, capture the returned
+ * NODE& reference.
+ *
+ * @note
+ * Actual dependency analysis is deferred to the sort() method, so
+ * you can add an arbitrary number of nodes without incurring analysis
+ * overhead for each. The flip side of this is that add()ing nodes that
+ * define a cycle leaves this object in a state in which sort() will
+ * always throw the Cycle exception.
+ *
+ * Two distinct use cases are anticipated:
+ * * The data used to load this object are completely known at compile
+ * time (e.g. LLEventPump listener names). A Cycle exception represents a
+ * bug which can be corrected by the coder. The program need neither catch
+ * Cycle nor attempt to salvage the state of this object.
+ * * The data are loaded at runtime, therefore the universe of
+ * dependencies cannot be known at compile time. The client code should
+ * catch Cycle.
+ * ** If a Cycle exception indicates fatally-flawed input data, this
+ * object can simply be discarded, possibly with the entire program run.
+ * ** If it is essential to restore this object to a working state, the
+ * simplest workaround is to remove() nodes in LIFO order.
+ * *** It may be useful to add functionality to this class to track the
+ * add() chronology, providing a pop() method to remove the most recently
+ * added node.
+ * *** It may further be useful to add a restore() method which would
+ * pop() until sort() no longer throws Cycle. This method would be
+ * expensive -- but it's not clear that client code could resolve the
+ * problem more cheaply.
+ */
+ NODE& add(const KEY& key, const NODE& node = NODE(),
+ const KeyList& after = KeyList(),
+ const KeyList& before = KeyList())
+ {
+ // Get the passed-in lists as sets for equality comparison
+ typename DepNode::dep_set
+ after_set(after.begin(), after.end()),
+ before_set(before.begin(), before.end());
+ // Try to insert the new node; if it already exists, find the old
+ // node instead.
+ std::pair<typename DepNodeMap::iterator, bool> inserted =
+ mNodes.insert(typename DepNodeMap::value_type(key,
+ DepNode(node, after_set, before_set)));
+ if (! inserted.second) // bool indicating success of insert()
+ {
+ // We already have a node by this name. Have its dependencies
+ // changed? If the existing node's dependencies are identical, the
+ // result will be unchanged, so we can leave the cache intact.
+ // Regardless of inserted.second, inserted.first is the iterator
+ // to the newly-inserted (or existing) map entry. Of course, that
+ // entry's second is the DepNode of interest.
+ if (inserted.first->second.after != after_set ||
+ inserted.first->second.before != before_set)
+ {
+ // Dependencies have changed: clear the cached result.
+ mCache.clear();
+ // save the new dependencies
+ inserted.first->second.after = after_set;
+ inserted.first->second.before = before_set;
+ }
+ }
+ else // this node is new
+ {
+ // This will change results.
+ mCache.clear();
+ }
+ return inserted.first->second.node;
+ }
+
+ /// the value of an iterator, showing both KEY and its NODE
+ typedef refpair<const KEY&, NODE&> value_type;
+ /// the value of a const_iterator
+ typedef refpair<const KEY&, const NODE&> const_value_type;
+
+private:
+ // Extract functors
+ static value_type value_extract(DepNodeMapEntry& entry)
+ {
+ return value_type(entry.first, entry.second.node);
+ }
+
+ static const_value_type const_value_extract(const DepNodeMapEntry& entry)
+ {
+ return const_value_type(entry.first, entry.second.node);
+ }
+
+ // All the iterator access methods return iterator ranges just to cut down
+ // on the friggin' boilerplate!!
+
+ /// generic mNodes range method
+ template<typename ITERATOR, typename FUNCTION>
+ boost::iterator_range<ITERATOR> generic_range(FUNCTION function)
+ {
+ return make_transform_range(mNodes, function);
+ }
+
+ /// generic mNodes const range method
+ template<typename ITERATOR, typename FUNCTION>
+ boost::iterator_range<ITERATOR> generic_range(FUNCTION function) const
+ {
+ return make_transform_range(mNodes, function);
+ }
+
+public:
+ /// iterator over value_type entries
+ typedef boost::transform_iterator<boost::function<value_type(DepNodeMapEntry&)>,
+ typename DepNodeMap::iterator> iterator;
+ /// range over value_type entries
+ typedef boost::iterator_range<iterator> range;
+
+ /// iterate over value_type <i>in @c KEY order</i> rather than dependency order
+ range get_range()
+ {
+ return generic_range<iterator>(value_extract);
+ }
+
+ /// iterator over const_value_type entries
+ typedef boost::transform_iterator<boost::function<const_value_type(const DepNodeMapEntry&)>,
+ typename DepNodeMap::const_iterator> const_iterator;
+ /// range over const_value_type entries
+ typedef boost::iterator_range<const_iterator> const_range;
+
+ /// iterate over const_value_type <i>in @c KEY order</i> rather than dependency order
+ const_range get_range() const
+ {
+ return generic_range<const_iterator>(const_value_extract);
+ }
+
+ /// iterator over stored NODEs
+ typedef boost::transform_iterator<boost::function<NODE&(DepNodeMapEntry&)>,
+ typename DepNodeMap::iterator> node_iterator;
+ /// range over stored NODEs
+ typedef boost::iterator_range<node_iterator> node_range;
+
+ /// iterate over NODE <i>in @c KEY order</i> rather than dependency order
+ node_range get_node_range()
+ {
+ // First take a DepNodeMapEntry and extract a reference to its
+ // DepNode, then from that extract a reference to its NODE.
+ return generic_range<node_iterator>(
+ boost::bind<NODE&>(&DepNode::node,
+ boost::bind<DepNode&>(&DepNodeMapEntry::second, _1)));
+ }
+
+ /// const iterator over stored NODEs
+ typedef boost::transform_iterator<boost::function<const NODE&(const DepNodeMapEntry&)>,
+ typename DepNodeMap::const_iterator> const_node_iterator;
+ /// const range over stored NODEs
+ typedef boost::iterator_range<const_node_iterator> const_node_range;
+
+ /// iterate over const NODE <i>in @c KEY order</i> rather than dependency order
+ const_node_range get_node_range() const
+ {
+ // First take a DepNodeMapEntry and extract a reference to its
+ // DepNode, then from that extract a reference to its NODE.
+ return generic_range<const_node_iterator>(
+ boost::bind<const NODE&>(&DepNode::node,
+ boost::bind<const DepNode&>(&DepNodeMapEntry::second, _1)));
+ }
+
+ /// const iterator over stored KEYs
+ typedef boost::transform_iterator<boost::function<const KEY&(const DepNodeMapEntry&)>,
+ typename DepNodeMap::const_iterator> const_key_iterator;
+ /// const range over stored KEYs
+ typedef boost::iterator_range<const_key_iterator> const_key_range;
+ // We don't provide a non-const iterator over KEYs because they should be
+ // immutable, and in fact our underlying std::map won't give us non-const
+ // references.
+
+ /// iterate over const KEY <i>in @c KEY order</i> rather than dependency order
+ const_key_range get_key_range() const
+ {
+ // From a DepNodeMapEntry, extract a reference to its KEY.
+ return generic_range<const_key_iterator>(
+ boost::bind<const KEY&>(&DepNodeMapEntry::first, _1));
+ }
+
+ /**
+ * Find an existing NODE, or return NULL. We decided to avoid providing a
+ * method analogous to std::map::find(), for a couple of reasons:
+ *
+ * * For a find-by-key, getting back an iterator to the (key, value) pair
+ * is less than useful, since you already have the key in hand.
+ * * For a failed request, comparing to end() is problematic. First, we
+ * provide range accessors, so it's more code to get end(). Second, we
+ * provide a number of different ranges -- quick, to which one's end()
+ * should we compare the iterator returned by find()?
+ *
+ * The returned pointer is solely to allow expressing the not-found
+ * condition. LLDependencies still owns the found NODE.
+ */
+ const NODE* get(const KEY& key) const
+ {
+ typename DepNodeMap::const_iterator found = mNodes.find(key);
+ if (found != mNodes.end())
+ {
+ return &found->second.node;
+ }
+ return NULL;
+ }
+
+ /**
+ * non-const get()
+ */
+ NODE* get(const KEY& key)
+ {
+ // Use const implementation, then cast away const-ness of return
+ return const_cast<NODE*>(const_cast<const self_type*>(this)->get(key));
+ }
+
+ /**
+ * Remove a node with specified key. This operation is the major reason
+ * we rebuild the graph on the fly instead of storing it.
+ */
+ bool remove(const KEY& key)
+ {
+ typename DepNodeMap::iterator found = mNodes.find(key);
+ if (found != mNodes.end())
+ {
+ mNodes.erase(found);
+ return true;
+ }
+ return false;
+ }
+
+private:
+ /// cached list of iterators
+ typedef std::vector<iterator> iterator_list;
+ typedef typename iterator_list::iterator iterator_list_iterator;
+
+public:
+ /**
+ * The return type of the sort() method needs some explanation. Provide a
+ * public typedef to facilitate storing the result.
+ *
+ * * We will prepare mCache by looking up DepNodeMap iterators.
+ * * We want to return a range containing iterators that will walk mCache.
+ * * If we simply stored DepNodeMap iterators and returned
+ * (mCache.begin(), mCache.end()), dereferencing each iterator would
+ * obtain a DepNodeMap iterator.
+ * * We want the caller to loop over @c value_type: pair<KEY, NODE>.
+ * * This requires two transformations:
+ * ** mCache must contain @c LLDependencies::iterator so that
+ * dereferencing each entry will obtain an @c LLDependencies::value_type
+ * rather than a DepNodeMapEntry.
+ * ** We must wrap mCache's iterators in boost::indirect_iterator so that
+ * dereferencing one of our returned iterators will also dereference the
+ * iterator contained in mCache.
+ */
+ typedef boost::iterator_range<boost::indirect_iterator<iterator_list_iterator> > sorted_range;
+ /// for convenience in looping over a sorted_range
+ typedef typename sorted_range::iterator sorted_iterator;
+
+ /**
+ * Once we've loaded in the dependencies of interest, arrange them into an
+ * order that works -- or throw Cycle exception.
+ *
+ * Return an iterator range over (key, node) pairs that traverses them in
+ * the desired order.
+ */
+ sorted_range sort() const
+ {
+ // Changes to mNodes cause us to clear our cache, so empty mCache
+ // means it's invalid and should be recomputed. However, if mNodes is
+ // also empty, then an empty mCache represents a valid order, so don't
+ // bother sorting.
+ if (mCache.empty() && ! mNodes.empty())
+ {
+ // Construct a map of node keys to distinct vertex numbers -- even for
+ // nodes mentioned only in before/after constraints, that haven't yet
+ // been explicitly added. Rely on std::map rejecting a second attempt
+ // to insert the same key. Use the map's size() as the vertex number
+ // to get a distinct value for each successful insertion.
+ typedef std::map<KEY, int> VertexMap;
+ VertexMap vmap;
+ // Nest each of these loops because !@#$%? MSVC warns us that its
+ // former broken behavior has finally been fixed -- and our builds
+ // treat warnings as errors.
+ {
+ for (typename DepNodeMap::const_iterator nmi = mNodes.begin(), nmend = mNodes.end();
+ nmi != nmend; ++nmi)
+ {
+ vmap.insert(typename VertexMap::value_type(nmi->first, vmap.size()));
+ for (typename DepNode::dep_set::const_iterator ai = nmi->second.after.begin(),
+ aend = nmi->second.after.end();
+ ai != aend; ++ai)
+ {
+ vmap.insert(typename VertexMap::value_type(*ai, vmap.size()));
+ }
+ for (typename DepNode::dep_set::const_iterator bi = nmi->second.before.begin(),
+ bend = nmi->second.before.end();
+ bi != bend; ++bi)
+ {
+ vmap.insert(typename VertexMap::value_type(*bi, vmap.size()));
+ }
+ }
+ }
+ // Define the edges. For this we must traverse mNodes again, mapping
+ // all the known key dependencies to integer pairs.
+ EdgeList edges;
+ {
+ for (typename DepNodeMap::const_iterator nmi = mNodes.begin(), nmend = mNodes.end();
+ nmi != nmend; ++nmi)
+ {
+ int thisnode = vmap[nmi->first];
+ // after dependencies: build edges from the named node to this one
+ for (typename DepNode::dep_set::const_iterator ai = nmi->second.after.begin(),
+ aend = nmi->second.after.end();
+ ai != aend; ++ai)
+ {
+ edges.push_back(EdgeList::value_type(vmap[*ai], thisnode));
+ }
+ // before dependencies: build edges from this node to the
+ // named one
+ for (typename DepNode::dep_set::const_iterator bi = nmi->second.before.begin(),
+ bend = nmi->second.before.end();
+ bi != bend; ++bi)
+ {
+ edges.push_back(EdgeList::value_type(thisnode, vmap[*bi]));
+ }
+ }
+ }
+ // Hide the gory details of our topological sort, since they shouldn't
+ // get reinstantiated for each distinct NODE type.
+ VertexList sorted(topo_sort(vmap.size(), edges));
+ // Build the reverse of vmap to look up the key for each vertex
+ // descriptor. vmap contains exactly one entry for each distinct key,
+ // and we're certain that the associated int values are distinct
+ // indexes. The fact that they're not in order is irrelevant.
+ KeyList vkeys(vmap.size());
+ for (typename VertexMap::const_iterator vmi = vmap.begin(), vmend = vmap.end();
+ vmi != vmend; ++vmi)
+ {
+ vkeys[vmi->second] = vmi->first;
+ }
+ // Walk the sorted output list, building the result into mCache so
+ // we'll have it next time someone asks.
+ mCache.clear();
+ for (VertexList::const_iterator svi = sorted.begin(), svend = sorted.end();
+ svi != svend; ++svi)
+ {
+ // We're certain that vkeys[*svi] exists. However, there might not
+ // yet be a corresponding entry in mNodes.
+ self_type* non_const_this(const_cast<self_type*>(this));
+ typename DepNodeMap::iterator found = non_const_this->mNodes.find(vkeys[*svi]);
+ if (found != non_const_this->mNodes.end())
+ {
+ // Make an iterator of appropriate type.
+ mCache.push_back(iterator(found, value_extract));
+ }
+ }
+ }
+ // Whether or not we've just recomputed mCache, it should now contain
+ // the results we want. Return a range of indirect_iterators over it
+ // so that dereferencing a returned iterator will dereference the
+ // iterator stored in mCache and directly reference the (key, node)
+ // pair.
+ boost::indirect_iterator<iterator_list_iterator>
+ begin(mCache.begin()),
+ end(mCache.end());
+ return sorted_range(begin, end);
+ }
+
+ /// Override base-class describe() with actual implementation
+ virtual std::ostream& describe(std::ostream& out, bool full=true) const
+ {
+ typename DepNodeMap::const_iterator dmi(mNodes.begin()), dmend(mNodes.end());
+ if (dmi != dmend)
+ {
+ std::string sep;
+ describe(out, sep, *dmi, full);
+ while (++dmi != dmend)
+ {
+ describe(out, sep, *dmi, full);
+ }
+ }
+ return out;
+ }
+
+ /// describe() helper: report a DepNodeEntry
+ static std::ostream& describe(std::ostream& out, std::string& sep,
+ const DepNodeMapEntry& entry, bool full)
+ {
+ // If we were asked for a full report, describe every node regardless
+ // of whether it has dependencies. If we were asked to suppress
+ // independent nodes, describe this one if either after or before is
+ // non-empty.
+ if (full || (! entry.second.after.empty()) || (! entry.second.before.empty()))
+ {
+ out << sep;
+ sep = "\n";
+ if (! entry.second.after.empty())
+ {
+ out << "after ";
+ describe(out, entry.second.after);
+ out << " -> ";
+ }
+ LLDependencies_describe(out, entry.first);
+ if (! entry.second.before.empty())
+ {
+ out << " -> before ";
+ describe(out, entry.second.before);
+ }
+ }
+ return out;
+ }
+
+ /// describe() helper: report a dep_set
+ static std::ostream& describe(std::ostream& out, const typename DepNode::dep_set& keys)
+ {
+ out << '(';
+ typename DepNode::dep_set::const_iterator ki(keys.begin()), kend(keys.end());
+ if (ki != kend)
+ {
+ LLDependencies_describe(out, *ki);
+ while (++ki != kend)
+ {
+ out << ", ";
+ LLDependencies_describe(out, *ki);
+ }
+ }
+ out << ')';
+ return out;
+ }
+
+ /// Iterator over the before/after KEYs on which a given NODE depends
+ typedef typename DepNode::dep_set::const_iterator dep_iterator;
+ /// range over the before/after KEYs on which a given NODE depends
+ typedef boost::iterator_range<dep_iterator> dep_range;
+
+ /// dependencies access from key
+ dep_range get_dep_range_from_key(const KEY& key, const dep_selector& selector) const
+ {
+ typename DepNodeMap::const_iterator found = mNodes.find(key);
+ if (found != mNodes.end())
+ {
+ return dep_range(selector(found->second));
+ }
+ // We want to return an empty range. On some platforms a default-
+ // constructed range (e.g. dep_range()) does NOT suffice! The client
+ // is likely to try to iterate from boost::begin(range) to
+ // boost::end(range); yet these iterators might not be valid. Instead
+ // return a range over a valid, empty container.
+ static const typename DepNode::dep_set empty_deps;
+ return dep_range(empty_deps.begin(), empty_deps.end());
+ }
+
+ /// dependencies access from any one of our key-order iterators
+ template<typename ITERATOR>
+ dep_range get_dep_range_from_xform(const ITERATOR& iterator, const dep_selector& selector) const
+ {
+ return dep_range(selector(iterator.base()->second));
+ }
+
+ /// dependencies access from sorted_iterator
+ dep_range get_dep_range_from_sorted(const sorted_iterator& sortiter,
+ const dep_selector& selector) const
+ {
+ // sorted_iterator is a boost::indirect_iterator wrapping an mCache
+ // iterator, which we can obtain by sortiter.base(). Deferencing that
+ // gets us an mCache entry, an 'iterator' -- one of our traversal
+ // iterators -- on which we can use get_dep_range_from_xform().
+ return get_dep_range_from_xform(*sortiter.base(), selector);
+ }
+
+ /**
+ * Get a range over the after KEYs stored for the passed KEY or iterator,
+ * in <i>arbitrary order.</i> If you pass a nonexistent KEY, returns empty
+ * range -- same as a KEY with no after KEYs. Detect existence of a KEY
+ * using get() instead.
+ */
+ template<typename KEY_OR_ITER>
+ dep_range get_after_range(const KEY_OR_ITER& key) const;
+
+ /**
+ * Get a range over the before KEYs stored for the passed KEY or iterator,
+ * in <i>arbitrary order.</i> If you pass a nonexistent KEY, returns empty
+ * range -- same as a KEY with no before KEYs. Detect existence of a KEY
+ * using get() instead.
+ */
+ template<typename KEY_OR_ITER>
+ dep_range get_before_range(const KEY_OR_ITER& key) const;
+
+private:
+ DepNodeMap mNodes;
+ mutable iterator_list mCache;
+};
+
+/**
+ * Functor to get a dep_range from a KEY or iterator -- generic case. If the
+ * passed value isn't one of our iterator specializations, assume it's
+ * convertible to the KEY type.
+ */
+template<typename KEY_ITER>
+struct LLDependencies_dep_range_from
+{
+ template<typename KEY, typename NODE, typename SELECTOR>
+ typename LLDependencies<KEY, NODE>::dep_range
+ operator()(const LLDependencies<KEY, NODE>& deps,
+ const KEY_ITER& key,
+ const SELECTOR& selector)
+ {
+ return deps.get_dep_range_from_key(key, selector);
+ }
+};
+
+/// Specialize LLDependencies_dep_range_from for our key-order iterators
+template<typename FUNCTION, typename ITERATOR>
+struct LLDependencies_dep_range_from< boost::transform_iterator<FUNCTION, ITERATOR> >
+{
+ template<typename KEY, typename NODE, typename SELECTOR>
+ typename LLDependencies<KEY, NODE>::dep_range
+ operator()(const LLDependencies<KEY, NODE>& deps,
+ const boost::transform_iterator<FUNCTION, ITERATOR>& iter,
+ const SELECTOR& selector)
+ {
+ return deps.get_dep_range_from_xform(iter, selector);
+ }
+};
+
+/// Specialize LLDependencies_dep_range_from for sorted_iterator
+template<typename BASEITER>
+struct LLDependencies_dep_range_from< boost::indirect_iterator<BASEITER> >
+{
+ template<typename KEY, typename NODE, typename SELECTOR>
+ typename LLDependencies<KEY, NODE>::dep_range
+ operator()(const LLDependencies<KEY, NODE>& deps,
+ const boost::indirect_iterator<BASEITER>& iter,
+ const SELECTOR& selector)
+ {
+ return deps.get_dep_range_from_sorted(iter, selector);
+ }
+};
+
+/// generic get_after_range() implementation
+template<typename KEY, typename NODE>
+template<typename KEY_OR_ITER>
+typename LLDependencies<KEY, NODE>::dep_range
+LLDependencies<KEY, NODE>::get_after_range(const KEY_OR_ITER& key_iter) const
+{
+ return LLDependencies_dep_range_from<KEY_OR_ITER>()(
+ *this,
+ key_iter,
+ boost::bind<const typename DepNode::dep_set&>(&DepNode::after, _1));
+}
+
+/// generic get_before_range() implementation
+template<typename KEY, typename NODE>
+template<typename KEY_OR_ITER>
+typename LLDependencies<KEY, NODE>::dep_range
+LLDependencies<KEY, NODE>::get_before_range(const KEY_OR_ITER& key_iter) const
+{
+ return LLDependencies_dep_range_from<KEY_OR_ITER>()(
+ *this,
+ key_iter,
+ boost::bind<const typename DepNode::dep_set&>(&DepNode::before, _1));
+}
+
+#endif /* ! defined(LL_LLDEPENDENCIES_H) */