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

   1 package org.spearce.jgit.lib;
   2
   3 import java.io.BufferedReader;
   4 import java.io.File;
   5 import java.io.FileInputStream;
   6 import java.io.FileNotFoundException;
   7 import java.io.FileReader;
   8 import java.io.IOException;
   9 import java.io.InputStream;
  10
  11 public class ObjectDatabase {
  12     private static final String[] refSearchPaths = { "", "refs/", "refs/tags/",
  13             "refs/heads/", };
  14
  15     private final File db;
  16
  17     private final File objectsDir;
  18
  19     public ObjectDatabase(final File d) {
  20         db = d.getAbsoluteFile();
  21         objectsDir = new File(db, "objects");
  22     }
  23
  24     private InputStream openObjectStream(final ObjectId objectId)
  25             throws IOException {
  26         try {
  27             final String n = objectId.toString();
  28             return new FileInputStream(new File(new File(objectsDir, n
  29                     .substring(0, 2)), n.substring(2)));
  30         } catch (FileNotFoundException fnfe) {
  31             return null;
  32         }
  33     }
  34
  35     public ObjectReader openBlob(final ObjectId id) throws IOException {
  36         final InputStream fis = openObjectStream(id);
  37         if (fis == null) {
  38             return null;
  39         }
  40
  41         try {
  42             final ObjectReader or = new ObjectReader(id, fis);
  43             if ("blob".equals(or.getType())) {
  44                 return or;
  45             } else {
  46                 throw new CorruptObjectException("Not a blob " + id);
  47             }
  48         } catch (IOException ioe) {
  49             fis.close();
  50             throw ioe;
  51         }
  52     }
  53
  54     public Commit openCommit(final ObjectId id) throws IOException {
  55         final InputStream fis = openObjectStream(id);
  56         if (fis == null) {
  57             return null;
  58         }
  59
  60         try {
  61             final ObjectReader or = new ObjectReader(id, fis);
  62             try {
  63                 if ("commit".equals(or.getType())) {
  64                     return new Commit(this, id, or.getBufferedReader());
  65                 } else {
  66                     throw new CorruptObjectException("Not a commit: " + id);
  67                 }
  68             } finally {
  69                 or.close();
  70             }
  71         } catch (IOException ioe) {
  72             fis.close();
  73             throw ioe;
  74         }
  75     }
  76
  77     public Tree openTree(final ObjectId id) throws IOException {
  78         final InputStream fis = openObjectStream(id);
  79         if (fis == null) {
  80             return null;
  81         }
  82
  83         try {
  84             final ObjectReader or = new ObjectReader(id, fis);
  85             try {
  86                 if ("commit".equals(or.getType())) {
  87                     return openTree(new Commit(this, id, or.getBufferedReader())
  88                             .getTreeId());
  89                 } else if ("tree".equals(or.getType())) {
  90                     return new Tree(this, id, or.getInputStream());
  91                 } else {
  92                     throw new CorruptObjectException("Not a tree-ish: " + id);
  93                 }
  94             } finally {
  95                 or.close();
  96             }
  97         } catch (IOException ioe) {
  98             fis.close();
  99             throw ioe;
 100         }
 101     }
 102
 103     private ObjectId readRef(final String name) throws IOException {
 104         final File f = new File(db, name);
 105         if (!f.isFile()) {
 106             return null;
 107         }
 108         final BufferedReader fr = new BufferedReader(new FileReader(f));
 109         try {
 110             final String line = fr.readLine();
 111             if (line == null || line.length() == 0) {
 112                 return null;
 113             }
 114             if (line.startsWith("ref: ")) {
 115                 return readRef(line.substring("ref: ".length()));
 116             }
 117             if (ObjectId.isId(line)) {
 118                 return new ObjectId(line);
 119             }
 120             throw new IOException("Not a ref: " + name + ": " + line);
 121         } finally {
 122             fr.close();
 123         }
 124     }
 125
 126     public ObjectId resolveRevision(final String r) throws IOException {
 127         ObjectId id = null;
 128
 129         if (ObjectId.isId(r)) {
 130             id = new ObjectId(r);
 131         }
 132         if (id == null) {
 133             for (int k = 0; k < refSearchPaths.length; k++) {
 134                 id = readRef(refSearchPaths[k] + r);
 135                 if (id != null) {
 136                     break;
 137                 }
 138             }
 139         }
 140         return id;
 141     }
 142
 143     public String toString() {
 144         return "ObjectDatabase[" + db + "]";
 145     }
 146 }