Add benchmark to test edge access time

• Add methods to select random nodes in the graph
• Add statistical analysis of values
• Add single edge access benchmark

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Migrated from D1831 (view on Phabricator)

I rebooted the azure VM and did the benchmark, here is the result for 1M edges:

        Command being timed: "java -Xmx220G -Xss10M -server -XX:PretenureSizeThreshold=512M -XX:MaxNewSize=4G -XX:+UseLargePages -XX:+UseTransparentHugePages -XX:+UseNUMA -XX:+UseTLAB -XX:+Re
sizeTLAB -cp swh-graph-0.0.1.jar org.softwareheritage.graph.benchmark.AccessEdge graph/compressed/all"                                                                                         
        User time (seconds): 316.50                                                                                                                                                            
        System time (seconds): 97.80                                                                                                                                                           
        Percent of CPU this job got: 16%                                                                                                                                                       
        Elapsed (wall clock) time (h:mm:ss or m:ss): 41:58.50                                                                                                                                  
        Average shared text size (kbytes): 0                                                                                                                                                   
        Average unshared data size (kbytes): 0                                                                                                                                                 
        Average stack size (kbytes): 0                                                                                                                                                         
        Average total size (kbytes): 0                                                                                                                                                         
        Maximum resident set size (kbytes): 124274776                                                                                                                                          
        Average resident set size (kbytes): 0                                                                                                                                                  
        Major (requiring I/O) page faults: 151                                                                                                                                                 
        Minor (reclaiming a frame) page faults: 314267                                                                                                                                         
        Voluntary context switches: 902158                                                                                                                                                     
        Involuntary context switches: 5357                                                                                                                                                     
        Swaps: 0                                                                                                                                                                               
        File system inputs: 223611496                                                                                                                                                          
        File system outputs: 2376                                                                                                                                                              
        Socket messages sent: 0                                                                                                                                                                
        Socket messages received: 0                                                                                                                                                            
        Signals delivered: 0                                                                                                                                                                   
        Page size (bytes): 4096                                                                                                                                                                
        Exit status: 0 

Used 1000000 random edges (results are in seconds):
min value: 2.0000000233721948E-7
max value: 0.001727816998027265
average: 1.0490578032659385E-6
standard deviation: 3.779805627909352E-6

Some references in the commit message have been migrated:

• T1885 is now #1885 (closed)

Add reference to #1885 (closed) in commit message.

Use LazyLongIterator instead of array in NeighborsIterator

Add method to pick random nodes with specific type

Merge request was merged

closed