Changeset 14857

Timestamp:

09/04/16 07:01:02 (6 years ago)

Author:

Mark Evenson

Message:

[PATCH 5/5] Support FILE-POSITION on string streams.
From cb667c106187443ff2d00bace14f0ee0686fe2fd Mon Sep 17 00:00:00 2001
Adds a custom, seekable writer to be able to go back in the written
output for STRING-OUTPUT-STREAM - the input case is slightly less
complex.
---

build.xml | 1 +
src/org/armedbear/lisp/SeekableStringWriter.java | 140 +++++++++++++++++++++
src/org/armedbear/lisp/StringInputStream.java | 43 ++++++-
src/org/armedbear/lisp/StringOutputStream.java | 35 +++++-
test/lisp/abcl/misc-tests.lisp | 11 +-
.../armedbear/lisp/SeekableStringWriterTest.java | 19 +++
6 files changed, 242 insertions(+), 7 deletions(-)
create mode 100644 src/org/armedbear/lisp/SeekableStringWriter.java
create mode 100644 test/src/org/armedbear/lisp/SeekableStringWriterTest.java

Location:

trunk/abcl

Files:

• build.xml (modified) (1 diff)
• src/org/armedbear/lisp/SeekableStringWriter.java (added)
• src/org/armedbear/lisp/StringInputStream.java (modified) (4 diffs)
• src/org/armedbear/lisp/StringOutputStream.java (modified) (3 diffs)
• test/lisp/abcl/misc-tests.lisp (modified) (1 diff)
• test/src/org/armedbear/lisp/SeekableStringWriterTest.java (added)

trunk/abcl/build.xml

@@ -947 +947 @@
         <arg value="org.armedbear.lisp.PathnameTest"/>
         <arg value="org.armedbear.lisp.StreamTest"/>
+        <arg value="org.armedbear.lisp.SeekableStringWriterTest"/>
         <arg value="org.armedbear.lisp.UtilitiesTest"/>
     <!-- currently hangs(!) the running process

trunk/abcl/src/org/armedbear/lisp/StringInputStream.java

@@ -36 +36 @@
 import static org.armedbear.lisp.Lisp.*;
 
+import java.io.IOException;
 import java.io.StringReader;
 
@@ -42 +43 @@
     private final StringReader stringReader;
     private final int start;
+    private final String subString;
     
     public StringInputStream(String s)
@@ -61 +63 @@
 
         this.start = start;
-        
-        stringReader = new StringReader(s.substring(start, end));
+
+        subString = s.substring(start, end);
+        stringReader = new StringReader(subString);
         initAsCharacterInputStream(stringReader);
     }
@@ -94 +97 @@
     @Override
     public int getOffset() {
-        return start + super.getOffset();
+        return start + offset;
+    }
+
+    @Override
+    protected long _getFilePosition() {
+        return getOffset();
+    }
+
+    @Override
+    protected boolean _setFilePosition(LispObject arg) {
+        try {
+            int offset;
+
+            if (arg == Keyword.START)
+                offset = 0;
+            else if (arg == Keyword.END)
+                offset = subString.length();
+            else {
+                long n = Fixnum.getValue(arg);
+                if (n < 0 || n > subString.length())
+                    error(new StreamError(this, "FILE-POSITION got out of bounds argument."));
+                offset = (int) n; // FIXME arg might be a bignum
+            }
+
+            stringReader.reset();
+            stringReader.skip(offset);
+            initAsCharacterInputStream(stringReader);
+
+            this.offset = offset;
+        }
+        catch (IOException e) {
+            error(new StreamError(this, e));
+        }
+
+        return true;
     }
     

trunk/abcl/src/org/armedbear/lisp/StringOutputStream.java

@@ -36 +36 @@
 import static org.armedbear.lisp.Lisp.*;
 
+import java.io.IOException;
 import java.io.StringWriter;
 
 public final class StringOutputStream extends Stream
 {
-    private final StringWriter stringWriter;
+    private final SeekableStringWriter stringWriter;
 
     public StringOutputStream()
@@ -52 +53 @@
         this.elementType = elementType;
         this.eolStyle = EolStyle.RAW;
-        initAsCharacterOutputStream(stringWriter = new StringWriter());
+        initAsCharacterOutputStream(stringWriter = new SeekableStringWriter());
     }
 
@@ -86 +87 @@
         if (elementType == NIL)
             return 0;
-        return stringWriter.getBuffer().length();
+        return offset;
+    }
+
+    @Override
+    protected boolean _setFilePosition(LispObject arg) {
+        if (elementType == NIL)
+            return false;
+
+        try {
+            int offset;
+
+            if (arg == Keyword.START)
+                offset = 0;
+            else if (arg == Keyword.END)
+                offset = stringWriter.getBuffer().length();
+            else {
+                long n = Fixnum.getValue(arg);
+                offset = (int) n; // FIXME arg might be a bignum
+            }
+
+            stringWriter.seek(offset);
+
+            this.offset = offset;
+        }
+        catch (IllegalArgumentException e) {
+            error(new StreamError(this, e));
+        }
+
+        return true;
     }
 

trunk/abcl/test/lisp/abcl/misc-tests.lisp

@@ -110 +110 @@
                                  (values 42 2))))))
   42 2)
+
+(deftest string-output-stream.seekable
+    (string= "Goodbye, World! Something."
+             (let ((stream (make-string-output-stream)))
+               (write-string "Hello, World!   Something." stream)
+               (file-position stream :start)
+               (write-string "Goodbye, World!" stream)
+               (get-output-stream-string stream)))
+  T)