Class ASCIIGraph
- java.lang.Object
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- it.unimi.dsi.big.webgraph.ImmutableGraph
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- it.unimi.dsi.big.webgraph.ImmutableSequentialGraph
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- it.unimi.dsi.big.webgraph.ASCIIGraph
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- All Implemented Interfaces:
it.unimi.dsi.lang.FlyweightPrototype<ImmutableGraph>
public class ASCIIGraph extends ImmutableSequentialGraph
AnImmutableGraph
that corresponds to graphs stored in a human-readable ASCII format where each line contains the list of successors of a given node.The file format is as follows: the graph is stored in a file named
basename.graph-txt
. The first line contains the number of nodes, n. Then, n lines follow, the i-th line containing the successors of node i in increasing order (nodes are numbered from 0 to n−1). Successors are separated by a single space.Contrarily to other classes, the load methods of this class do not always return instances of this class. In particular,
loadOffline(CharSequence)
andloadOnce(InputStream)
will return an instance of this class for offline access. The instance will not provide random access, but sequential access will be backed by the original text file and only one array of successor will be loaded in core memory at any time.The
load(CharSequence)
method, on the other hand, will return a wrapped instance ofArrayListMutableGraph
built by copying a wrapped offline instance of this class.Using
ASCIIGraph
to convert your dataA simple (albeit rather inefficient) way to import data into WebGraph is using ASCII graphs. Suppose you create the following file, named
example.graph-txt
:2 1 0 1
Then, the commandjava it.unimi.dsi.webgraph.BVGraph -g ASCIIGraph example bvexample
will produce a compressed graph inBVGraph
format with basenamebvexample
. Even more convenient is theloadOnce(InputStream)
method, which reads from an input stream an ASCII graph and exposes it for a single traversal. It can be used, for instance, with the main method ofBVGraph
to generate somehow an ASCII graph and store it in compressed form on the fly. The previous example could be then rewritten asjava it.unimi.dsi.webgraph.BVGraph -1 -g ASCIIGraph dummy bvexample <example.graph-txt
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Nested Class Summary
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Nested classes/interfaces inherited from class it.unimi.dsi.big.webgraph.ImmutableGraph
ImmutableGraph.LoadMethod
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Field Summary
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Fields inherited from class it.unimi.dsi.big.webgraph.ImmutableGraph
GRAPHCLASS_PROPERTY_KEY, NUMBER_OF_THREADS_PROPERTY, PROPERTIES_EXTENSION
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Constructor Summary
Constructors Modifier Constructor Description ASCIIGraph(java.io.InputStream is)
Creates a read-once ASCII graph.protected
ASCIIGraph(java.lang.CharSequence graphFile)
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description static ImmutableGraph
load(java.lang.CharSequence basename)
static ImmutableGraph
load(java.lang.CharSequence basename, it.unimi.dsi.logging.ProgressLogger unused)
static ASCIIGraph
loadMapped(java.lang.CharSequence basename)
static ASCIIGraph
loadMapped(java.lang.CharSequence basename, it.unimi.dsi.logging.ProgressLogger unused)
static ASCIIGraph
loadOffline(java.lang.CharSequence basename)
static ASCIIGraph
loadOffline(java.lang.CharSequence basename, it.unimi.dsi.logging.ProgressLogger unused)
static ASCIIGraph
loadOnce(java.io.InputStream is)
static ImmutableGraph
loadSequential(java.lang.CharSequence basename)
Deprecated.static ASCIIGraph
loadSequential(java.lang.CharSequence basename, it.unimi.dsi.logging.ProgressLogger unused)
Deprecated.static void
main(java.lang.String[] args)
NodeIterator
nodeIterator(long from)
Returns a node iterator for scanning the graph sequentially, starting from the given node.long
numNodes()
Returns the number of nodes of this graph.static void
store(ImmutableGraph graph, java.lang.CharSequence basename)
static void
store(ImmutableGraph graph, java.lang.CharSequence basename, it.unimi.dsi.logging.ProgressLogger unused)
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Methods inherited from class it.unimi.dsi.big.webgraph.ImmutableSequentialGraph
copy, outdegree, randomAccess, successorBigArray
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Methods inherited from class it.unimi.dsi.big.webgraph.ImmutableGraph
basename, equals, hasCopiableIterators, hashCode, intNumNodes, load, nodeIterator, numArcs, outdegrees, splitNodeIterators, store, store, successors, toString, wrap, wrap
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Constructor Detail
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ASCIIGraph
protected ASCIIGraph(java.lang.CharSequence graphFile) throws java.lang.NumberFormatException, java.io.IOException
- Throws:
java.lang.NumberFormatException
java.io.IOException
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ASCIIGraph
public ASCIIGraph(java.io.InputStream is) throws java.lang.NumberFormatException, java.io.IOException
Creates a read-once ASCII graph. Instances created using this constructor can be only accessed using a single call tonodeIterator(long)
.- Parameters:
is
- an input stream containing an ASCII graph.- Throws:
java.lang.NumberFormatException
java.io.IOException
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Method Detail
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numNodes
public long numNodes()
Description copied from class:ImmutableGraph
Returns the number of nodes of this graph.Albeit this method is not optional, it is allowed that this method throws an
UnsupportedOperationException
if this graph has never been entirely traversed using anode iterator
. This apparently bizarre behaviour is necessary to support implementations asArcListASCIIGraph
, which do not know the actual number of nodes until a traversal has been completed.- Specified by:
numNodes
in classImmutableGraph
- Returns:
- the number of nodes.
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nodeIterator
public NodeIterator nodeIterator(long from)
Description copied from class:ImmutableGraph
Returns a node iterator for scanning the graph sequentially, starting from the given node.- Overrides:
nodeIterator
in classImmutableSequentialGraph
- Parameters:
from
- the node from which the iterator will iterate.- Returns:
- a
NodeIterator
for accessing nodes and successors sequentially.
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loadSequential
@Deprecated public static ImmutableGraph loadSequential(java.lang.CharSequence basename) throws java.io.IOException
Deprecated.- Throws:
java.io.IOException
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loadSequential
@Deprecated public static ASCIIGraph loadSequential(java.lang.CharSequence basename, it.unimi.dsi.logging.ProgressLogger unused) throws java.io.IOException
Deprecated.- Throws:
java.io.IOException
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loadOffline
public static ASCIIGraph loadOffline(java.lang.CharSequence basename) throws java.io.IOException
- Throws:
java.io.IOException
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loadOffline
public static ASCIIGraph loadOffline(java.lang.CharSequence basename, it.unimi.dsi.logging.ProgressLogger unused) throws java.io.IOException
- Throws:
java.io.IOException
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loadMapped
public static ASCIIGraph loadMapped(java.lang.CharSequence basename) throws java.io.IOException
- Throws:
java.io.IOException
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loadMapped
public static ASCIIGraph loadMapped(java.lang.CharSequence basename, it.unimi.dsi.logging.ProgressLogger unused) throws java.io.IOException
- Throws:
java.io.IOException
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loadOnce
public static ASCIIGraph loadOnce(java.io.InputStream is) throws java.io.IOException
- Throws:
java.io.IOException
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load
public static ImmutableGraph load(java.lang.CharSequence basename) throws java.io.IOException
- Throws:
java.io.IOException
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load
public static ImmutableGraph load(java.lang.CharSequence basename, it.unimi.dsi.logging.ProgressLogger unused) throws java.io.IOException
- Throws:
java.io.IOException
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store
public static void store(ImmutableGraph graph, java.lang.CharSequence basename, it.unimi.dsi.logging.ProgressLogger unused) throws java.io.IOException
- Throws:
java.io.IOException
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store
public static void store(ImmutableGraph graph, java.lang.CharSequence basename) throws java.io.IOException
- Throws:
java.io.IOException
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main
public static void main(java.lang.String[] args) throws java.lang.IllegalArgumentException, java.lang.SecurityException, java.lang.IllegalAccessException, java.lang.reflect.InvocationTargetException, java.lang.NoSuchMethodException, java.io.IOException, com.martiansoftware.jsap.JSAPException, java.lang.ClassNotFoundException, java.lang.InstantiationException
- Throws:
java.lang.IllegalArgumentException
java.lang.SecurityException
java.lang.IllegalAccessException
java.lang.reflect.InvocationTargetException
java.lang.NoSuchMethodException
java.io.IOException
com.martiansoftware.jsap.JSAPException
java.lang.ClassNotFoundException
java.lang.InstantiationException
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