mbakhoff

# server/solr/logs/core.properties
# file is empty

mbakhoff

Thread 38 "wlfreerdp" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffdb7fe640 (LWP 510165)]
__memcpy_avx_unaligned_erms () at ../sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S:413
413             VMOVU   %VEC(0), (%rdi)
(gdb) backtrace 
#0  __memcpy_avx_unaligned_erms () at ../sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S:413
#1  0x0000555555559410 in wlf_copy_image (src=0x7fffe1940030, srcStride=7680, srcWidth=1920, srcHeight=1019, dst=0x7fffd910e000, dstStride=7680, dstWidth=1920, dstHeight=1019, area=0x7fffdb7fd8d0, scale=0)
    at /usr/src/debug/net-misc/freerdp-2.8.0/freerdp-2.8.0/client/Wayland/wlfreerdp.c:710
#2  0x0000555555557ca7 in wl_update_buffer (context_w=0x5555555783d0, ix=288, iy=976, iw=64, ih=43) at /usr/src/debug/net-misc/freerdp-2.8.0/freerdp-2.8.0/client/Wayland/wlfreerdp.c:108
#3  0x0000555555557e85 in wl_end_paint (context=0x5555555783d0) at /usr/src/debug/net-misc/freerdp-2.8.0/freerdp-2.8.0/client/Wayland/wlfreerdp.c:151

mbakhoff

How does a hashmap work?

A map contains key-value pairs. 
Pairs can be added and values can be looked up by the key.
Adding a key-value pair when the key already exists in the map will replace the existing value.

A naive map holds a list of key-value pairs: List<Pair<KeyType, ValueType>>.
To look up a value, each key-value pair in the list must be inspected.
When the number of pairs gets large, then the lookups will get slow.

mbakhoff

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;

class ClientHandler implements Runnable {
  
  private final Socket s;
  
  public ClientHandler(Socket s) {

mbakhoff

import java.util.Scanner;

class Scratch {

  public static void main(String[] args) {

    Node n1 = new Node(1);
    n1.add(2);
    n1.add(3);
    n1.add(4);

mbakhoff

package ee.ut.derpcode;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

mbakhoff

package ee.ut.derpcode;

import java.io.UnsupportedEncodingException;
import java.util.Date;

import java.util.Properties;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;