Remove upper bound on how many bytes/characters can be read

The limit was added to prevent people creating arbitrarily large buffers
(for instance, handle.read(2^31) would create a 2GB char array). For
"large" counts, we now read in blocks of size 8192, adding to an
extendable buffer.

src/main/java/dan200/computercraft/core/apis/handles/BinaryInputHandle.java

@@ -5,6 +5,7 @@
 import dan200.computercraft.api.lua.LuaException;
 
 import javax.annotation.Nonnull;
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Arrays;
@@ -13,6 +14,8 @@
 
 public class BinaryInputHandle extends HandleGeneric
 {
+    private static final int BUFFER_SIZE = 8192;
+
     private final InputStream m_stream;
 
     public BinaryInputHandle( InputStream reader )
@@ -45,16 +48,46 @@ public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull O
                     if( args.length > 0 && args[ 0 ] != null )
                     {
                         int count = getInt( args, 0 );
-                        if( count <= 0 || count >= 1024 * 16 )
+                        if( count < 0 )
                         {
-                            throw new LuaException( "Count out of range" );
+                            // Whilst this may seem absurd to allow reading 0 bytes, PUC Lua it so 
+                            // it seems best to remain somewhat consistent.
+                            throw new LuaException( "Cannot read a negative number of bytes" );
                         }
+                        else if( count <= BUFFER_SIZE )
+                        {
+                            // If we've got a small count, then allocate that and read it.
+                            byte[] bytes = new byte[ count ];
+                            int read = m_stream.read( bytes );
+
+                            if( read < 0 ) return null;
+                            if( read < count ) bytes = Arrays.copyOf( bytes, read );
+                            return new Object[] { bytes };
+                        }
+                        else
+                        {
+                            byte[] buffer = new byte[ BUFFER_SIZE ];
 
-                        byte[] bytes = new byte[ count ];
-                        count = m_stream.read( bytes );
-                        if( count < 0 ) return null;
-                        if( count < bytes.length ) bytes = Arrays.copyOf( bytes, count );
-                        return new Object[] { bytes };
+                            // Read the initial set of bytes, failing if none are read.
+                            int read = m_stream.read( buffer, 0, Math.min( buffer.length, count ) );
+                            if( read == -1 ) return null;
+
+                            ByteArrayOutputStream out = new ByteArrayOutputStream( read );
+                            count -= read;
+                            out.write( buffer, 0, read );
+
+                            // Otherwise read until we either reach the limit or we no longer consume
+                            // the full buffer.
+                            while( read >= buffer.length && count > 0 )
+                            {
+                                read = m_stream.read( buffer, 0, Math.min( BUFFER_SIZE, count ) );
+                                if( read == -1 ) break;
+                                count -= read;
+                                out.write( buffer, 0, read );
+                            }
+
+                            return new Object[] { out.toByteArray() };
+                        }
                     }
                     else
                     {

src/main/java/dan200/computercraft/core/apis/handles/EncodedInputHandle.java

@@ -6,10 +6,12 @@
 import javax.annotation.Nonnull;
 import java.io.*;
 
-import static dan200.computercraft.core.apis.ArgumentHelper.*;
+import static dan200.computercraft.core.apis.ArgumentHelper.optInt;
 
 public class EncodedInputHandle extends HandleGeneric
 {
+    private static final int BUFFER_SIZE = 8192;
+
     private final BufferedReader m_reader;
 
     public EncodedInputHandle( BufferedReader reader )
@@ -111,15 +113,45 @@ public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull O
                 try
                 {
                     int count = optInt( args, 0, 1 );
-                    if( count <= 0 || count >= 1024 * 16 )
+                    if( count < 0 )
+                    {
+                        // Whilst this may seem absurd to allow reading 0 characters, PUC Lua it so 
+                        // it seems best to remain somewhat consistent.
+                        throw new LuaException( "Cannot read a negative number of characters" );
+                    }
+                    else if( count <= BUFFER_SIZE )
+                    {
+                        // If we've got a small count, then allocate that and read it.
+                        char[] chars = new char[ count ];
+                        int read = m_reader.read( chars );
+
+                        return read < 0 ? null : new Object[] { new String( chars, 0, read ) };
+                    }
+                    else
                     {
-                        throw new LuaException( "Count out of range" );
+                        // If we've got a large count, read in bunches of 8192.
+                        char[] buffer = new char[ BUFFER_SIZE ];
+
+                        // Read the initial set of characters, failing if none are read.
+                        int read = m_reader.read( buffer, 0, Math.min( buffer.length, count ) );
+                        if( read == -1 ) return null;
+
+                        StringBuilder out = new StringBuilder( read );
+                        count -= read;
+                        out.append( buffer, 0, read );
+
+                        // Otherwise read until we either reach the limit or we no longer consume
+                        // the full buffer.
+                        while( read >= BUFFER_SIZE && count > 0 )
+                        {
+                            read = m_reader.read( buffer, 0, Math.min( BUFFER_SIZE, count ) );
+                            if( read == -1 ) break;
+                            count -= read;
+                            out.append( buffer, 0, read );
+                        }
+
+                        return new Object[] { out.toString() };
                     }
-                    char[] bytes = new char[ count ];
-                    count = m_reader.read( bytes );
-                    if( count < 0 ) return null;
-                    String str = new String( bytes, 0, count );
-                    return new Object[] { str };
                 }
                 catch( IOException e )
                 {