package gov.nasa.gsfc.spdf.cdfj; import java.nio.*; import java.io.*; import java.net.*; import java.nio.channels.*; import java.util.zip.*; import java.util.*; /** * CDFFactory creates an instance of CDFImpl from a CDF source. * The source CDF can be a file, a byte array, or a URL. */ public final class CDFFactory { public static final long CDF3_MAGIC =((long)0xcdf3 << 48) + ((long)0x0001 << 32) + 0x0000ffff; public static final long CDF3_COMPRESSED_MAGIC =((long)0xcdf3 << 48) + ((long)0x0001 << 32) + 0x00000000cccc0001l; public static final long CDF2_MAGIC =((long)0xcdf2 << 48) + ((long)0x0001 << 32) + 0x0000ffff; public static final long CDF2_MAGIC_DOT5 = ((long)0x0000ffff << 32) + 0x0000ffff; static Map cdfMap = Collections.synchronizedMap(new WeakHashMap()); static Long maxMappedMemory; private CDFFactory() { } /** * creates CDFImpl object from a byte array. */ static CDFImpl getCDF(byte [] ba) throws Throwable { ByteBuffer buf; synchronized (ba) { buf = ByteBuffer.allocateDirect(ba.length); buf.put(ba); } buf.flip(); return getVersion(buf); } static CDFImpl getCDF(ByteBuffer buf) throws Throwable { ByteBuffer rbuf; synchronized (buf) { ByteBuffer _buf = ByteBuffer.allocateDirect(buf.remaining()); _buf.put(buf); _buf.position(0); rbuf = _buf.asReadOnlyBuffer(); rbuf.order(buf.order()); } return getVersion(rbuf); } static CDFImpl getVersion(ByteBuffer buf) throws Throwable { LongBuffer lbuf = buf.asLongBuffer(); long magic = lbuf.get(); if (magic == CDF3_MAGIC) { return new CDF3Impl(buf); } if (magic == CDF3_COMPRESSED_MAGIC) { ByteBuffer mbuf = uncompressed(buf, 3); return new CDF3Impl(mbuf); } if (magic == CDF2_MAGIC_DOT5) { int release = buf.getInt(24); return new CDF2Impl(buf, release); } else { ShortBuffer sbuf = buf.asShortBuffer(); if (sbuf.get() == (short)0xcdf2) { if (sbuf.get() == (short)0x6002) { short x = sbuf.get(); if (x == 0) { if (sbuf.get() == -1) { return new CDF2Impl(buf, 6); } } else { if ((x == (short)0xcccc) && (sbuf.get() == 1)) { // is compressed - positioned at CCR ByteBuffer mbuf = uncompressed(buf, 2); return new CDF2Impl(mbuf, 6); } } } } } return null; } /** * creates CDFImpl object from a file. */ public static CDFImpl getCDF(String fname) throws Throwable { return getCDF(fname, false); } static CDFImpl getCDF(final String fname, final boolean option) throws Throwable { clean(); File file = new File(fname); final String _fname = file.getPath(); FileInputStream fis = new FileInputStream(file); FileChannel ch = fis.getChannel(); ByteBuffer buf = ch.map(FileChannel.MapMode.READ_ONLY, 0, ch.size()); fis.close(); CDFImpl cdf = getVersion(buf); if ( cdf==null ) { throw new CDFException.ReaderError("File is not a CDF-format file: "+fname); } ((CDFImpl)cdf).setOption(new ProcessingOption() { public String missingRecordOption() { if (option) return "accept"; return "reject"; } }); ((CDFImpl)cdf).setSource(new CDFSource() { public String getName() {return _fname;}; public boolean isFile() {return true;}; }); cdfMap.put(cdf, _fname); return cdf; } /** * creates CDFImpl object from a URL. */ static CDFImpl getCDF(URL url) throws Throwable { final String _url = url.toString(); URLConnection con = new CDFUrl(url).openConnection(); int remaining = con.getContentLength(); InputStream is = con.getInputStream(); byte [] ba = new byte[remaining]; int offset = 0; while (remaining > 0) { int got = is.read(ba, offset, remaining); offset += got; remaining -= got; } CDFImpl cdf = getCDF(ba); if ( cdf==null ) { throw new IllegalArgumentException("File is not a CDF-format file: "+url); } cdf.setSource(new CDFSource() { public String getName() {return _url;}; public boolean isFile() {return false;}; }); return cdf; } static ByteBuffer uncompressed(ByteBuffer buf, int version) { int DATA_OFFSET = 8 + 20; if (version == 3) DATA_OFFSET = 8 + 32; byte[] ba; int offset; int len = buf.getInt(8) - 20; if (version == 3) len = (int)(buf.getLong(8) - 32); int ulen = buf.getInt(8 + 12); if (version == 3) ulen = (int)(buf.getLong(8 + 20)); byte [] udata = new byte[ulen + 8]; buf.get(udata, 0, 8); // copy the magic words if (!buf.hasArray()) { // read data into byte array ba = new byte[len]; buf.position(DATA_OFFSET); buf.get(ba); offset = 0; } else { ba = buf.array(); offset = DATA_OFFSET; } int n = 0; try { ByteArrayInputStream bais = new ByteArrayInputStream(ba, offset, len); GZIPInputStream gz = new GZIPInputStream(bais); int toRead = udata.length - 8; int off = 8; while (toRead > 0) { n = gz.read(udata, off, toRead); if (n == -1) break; off += n; toRead -= n; } } catch (IOException ex) { System.out.println(ex.toString()); return null; } if (n < 0) return null; return ByteBuffer.wrap(udata); } public static class ProcessingOption { String missingRecordsOption() {return "reject";} } public static class CDFSource { public String getName() {return "";}; public boolean isFile() {return false;}; public boolean isURL() {return false;}; public boolean isByteArray() {return false;}; public boolean isByteBuffer() {return false;}; } private static long mappedMemoryUsed() { if (cdfMap.size() == 0) return 0; Set set = cdfMap.keySet(); Iterator it = set.iterator(); long size = 0; while (it.hasNext()) { size += ((CDFImpl)it.next()).getBuffer().limit(); } return size; } public static void setMaxMappedMemory(long value) { if (maxMappedMemory != null) { if (maxMappedMemory.longValue() > value) return; } maxMappedMemory = new Long(value); } public static void clean() { if (maxMappedMemory != null) { if (mappedMemoryUsed() > maxMappedMemory.longValue()) { System.gc(); } } } }