src/org/spearce/jgit/lib/WriteTree.java

   1 package org.spearce.jgit.lib;
   2
   3 import java.io.ByteArrayInputStream;
   4 import java.io.ByteArrayOutputStream;
   5 import java.io.File;
   6 import java.io.FileInputStream;
   7 import java.io.FileOutputStream;
   8 import java.io.IOException;
   9 import java.io.InputStream;
  10 import java.io.UnsupportedEncodingException;
  11 import java.security.MessageDigest;
  12 import java.security.NoSuchAlgorithmException;
  13 import java.util.ArrayList;
  14 import java.util.Collections;
  15 import java.util.Iterator;
  16 import java.util.zip.DeflaterOutputStream;
  17
  18 public class WriteTree extends TreeVisitor {
  19     private static final TreeNameComparator TNC = new TreeNameComparator();
  20
  21     private static final byte[] TREE_MODE;
  22
  23     private static final byte[] SYMLINK_MODE;
  24
  25     private static final byte[] PLAIN_FILE_MODE;
  26
  27     private static final byte[] EXECUTABLE_FILE_MODE;
  28
  29     static {
  30         try {
  31             TREE_MODE = "40000".getBytes("UTF-8");
  32             SYMLINK_MODE = "120000".getBytes("UTF-8");
  33             PLAIN_FILE_MODE = "100644".getBytes("UTF-8");
  34             EXECUTABLE_FILE_MODE = "100755".getBytes("UTF-8");
  35         } catch (UnsupportedEncodingException uue) {
  36             throw new ExceptionInInitializerError(uue);
  37         }
  38     }
  39
  40     private final ObjectDatabase objdb;
  41
  42     private final byte[] copybuf;
  43
  44     private final MessageDigest md;
  45
  46     private final boolean writeAll;
  47
  48     private File src;
  49
  50     public WriteTree(final ObjectDatabase db, final File sourceDir)
  51             throws NoSuchAlgorithmException {
  52         objdb = db;
  53         copybuf = new byte[8192];
  54         md = MessageDigest.getInstance("SHA-1");
  55         writeAll = true;
  56         src = sourceDir;
  57     }
  58
  59     protected void visitFile(final FileTreeEntry f) throws IOException {
  60         super.visitFile(f);
  61         final File d = new File(src, f.getName());
  62         final FileInputStream is = new FileInputStream(d);
  63         try {
  64             f.setId(writeObject("blob", (int) d.length(), is));
  65         } finally {
  66             is.close();
  67         }
  68     }
  69
  70     protected void visitSymlink(final SymlinkTreeEntry s) throws IOException {
  71         super.visitSymlink(s);
  72
  73         if (!objdb.checkObject(s.getId())) {
  74             throw new CorruptObjectException("Missing symlink blob "
  75                     + s.getId());
  76         }
  77     }
  78
  79     protected void visitTree(final Tree t) throws IOException {
  80         // Only visit a tree if it has been modified. If any child of a tree has
  81         // been modified then the tree itself will also appear modified;
  82         // consequently we will recurse into it.
  83         //
  84         if (writeAll || t.isModified()) {
  85             if (t.isRoot()) {
  86                 super.visitTree(t);
  87             } else {
  88                 final File d = new File(src, t.getName());
  89                 final File o = src;
  90                 src = d;
  91                 super.visitTree(t);
  92                 src = o;
  93             }
  94
  95             final ByteArrayOutputStream o = new ByteArrayOutputStream();
  96             final ArrayList r = new ArrayList();
  97             final byte[] d;
  98             Iterator i;
  99
 100             i = t.entryIterator();
 101             while (i.hasNext()) {
 102                 r.add(i.next());
 103             }
 104             Collections.sort(r, TNC);
 105
 106             i = r.iterator();
 107             while (i.hasNext()) {
 108                 final TreeEntry e = (TreeEntry) i.next();
 109                 final byte[] mode;
 110
 111                 if (e instanceof Tree) {
 112                     mode = TREE_MODE;
 113                 } else if (e instanceof SymlinkTreeEntry) {
 114                     mode = SYMLINK_MODE;
 115                 } else if (e instanceof FileTreeEntry) {
 116                     mode = ((FileTreeEntry) e).isExecutable() ? EXECUTABLE_FILE_MODE
 117                             : PLAIN_FILE_MODE;
 118                 } else {
 119                     throw new IOException("Object not supported in Tree:" + e);
 120                 }
 121
 122                 o.write(mode);
 123                 o.write(' ');
 124                 o.write(e.getNameUTF8());
 125                 o.write(0);
 126                 o.write(e.getId().getBytes());
 127             }
 128             d = o.toByteArray();
 129             t.setId(writeObject("tree", d.length, new ByteArrayInputStream(d)));
 130         }
 131     }
 132
 133     private ObjectId writeObject(final String type, int len,
 134             final InputStream is) throws IOException {
 135         final File t = File.createTempFile("noz", null, objdb
 136                 .getObjectsDirectory());
 137         final DeflaterOutputStream ts = new DeflaterOutputStream(
 138                 new FileOutputStream(t));
 139         ObjectId id = null;
 140         try {
 141             final byte[] header = (type + " " + len + "\0").getBytes("UTF-8");
 142             int r;
 143
 144             md.update(header);
 145             ts.write(header);
 146
 147             while ((r = is.read(copybuf)) > 0 && len > 0) {
 148                 if (r > len) {
 149                     r = len;
 150                 }
 151                 md.update(copybuf, 0, r);
 152                 ts.write(copybuf, 0, r);
 153                 len -= r;
 154             }
 155             if (len != 0) {
 156                 throw new CorruptObjectException("Input was short: " + len);
 157             }
 158
 159             ts.close();
 160             id = new ObjectId(md.digest());
 161         } finally {
 162             if (id == null) {
 163                 md.reset();
 164                 ts.close();
 165                 t.delete();
 166             }
 167         }
 168
 169         if (objdb.checkObject(id)) {
 170             // Object is already in the repository so remove the temporary file.
 171             //
 172             t.delete();
 173         } else {
 174             final File o = objdb.objectFile(id);
 175             o.getParentFile().mkdir();
 176             if (!t.renameTo(o)) {
 177                 if (!objdb.checkObject(id)) {
 178                     // The object failed to be renamed into its proper location
 179                     // and it doesn't exist in the repository either. (The
 180                     // rename could have failed if another process was placing
 181                     // the object there at the same time as us.) We really don't
 182                     // know what went wrong, so abort.
 183                     //
 184                     t.delete();
 185                     throw new IOException("Failed to write object " + id);
 186                 }
 187             }
 188         }
 189
 190         return id;
 191     }
 192 }