diff options
Diffstat (limited to 'app/src/main/java/github/daneren2005/dsub/util/tags/Common.java')
| -rw-r--r-- | app/src/main/java/github/daneren2005/dsub/util/tags/Common.java | 151 |
1 files changed, 98 insertions, 53 deletions
diff --git a/app/src/main/java/github/daneren2005/dsub/util/tags/Common.java b/app/src/main/java/github/daneren2005/dsub/util/tags/Common.java index 51344d90..c0d661f5 100644 --- a/app/src/main/java/github/daneren2005/dsub/util/tags/Common.java +++ b/app/src/main/java/github/daneren2005/dsub/util/tags/Common.java @@ -21,18 +21,14 @@ package github.daneren2005.dsub.util.tags; import java.io.IOException; import java.io.RandomAccessFile; import java.util.HashMap; -import java.util.Vector; +import java.util.ArrayList; public class Common { - private static final long MAX_PKT_SIZE = 524288; - - public void xdie(String reason) throws IOException { - throw new IOException(reason); - } - - /* - ** Returns a 32bit int from given byte offset in LE - */ + private static final int MAX_COMMENT_SIZE = 512; + + /** + * Returns a 32bit int from given byte offset in LE + */ public int b2le32(byte[] b, int off) { int r = 0; for(int i=0; i<4; i++) { @@ -40,7 +36,17 @@ public class Common { } return r; } - + + /** + * Same as b2le32 but reads from a RandomAccessFile instead of a buffer + */ + public int raf2le32(RandomAccessFile fh, long off) throws IOException { + byte[] scratch = new byte[4]; + fh.seek(off); + fh.read(scratch); + return b2le32(scratch, 0); + } + public int b2be32(byte[] b, int off) { return swap32(b2le32(b, off)); } @@ -48,63 +54,102 @@ public class Common { public int swap32(int i) { return((i&0xff)<<24)+((i&0xff00)<<8)+((i&0xff0000)>>8)+((i>>24)&0xff); } - - /* - ** convert 'byte' value into unsigned int - */ + + /** + * Returns a 16bit int from given byte offset in LE + */ + public int b2le16(byte[] b, int off) { + return ( b2u(b[off]) | b2u(b[off+1]) << 8 ); + } + + /** + * convert 'byte' value into unsigned int + */ public int b2u(byte x) { return (x & 0xFF); } - /* - ** Printout debug message to STDOUT - */ + /** + * Printout debug message to STDOUT + */ public void debug(String s) { System.out.println("DBUG "+s); } - - public HashMap parse_vorbis_comment(RandomAccessFile s, long offset, long payload_len) throws IOException { + + /** + * Throws an exception, killing the parser + */ + public void xdie(String reason) throws IOException { + throw new IOException(reason); + } + + public HashMap parse_vorbis_comment(RandomAccessFile fh, PageInfo.PageParser pp, long offset, long payload_len) throws IOException { HashMap tags = new HashMap(); - int comments = 0; // number of found comments - int xoff = 0; // offset within 'scratch' - int can_read = (int)(payload_len > MAX_PKT_SIZE ? MAX_PKT_SIZE : payload_len); - byte[] scratch = new byte[can_read]; - - // seek to given position and slurp in the payload - s.seek(offset); - s.read(scratch); - - // skip vendor string in format: [LEN][VENDOR_STRING] - xoff += 4 + b2le32(scratch, xoff); // 4 = LEN = 32bit int - comments = b2le32(scratch, xoff); - xoff += 4; - - // debug("comments count = "+comments); - for(int i=0; i<comments; i++) { - - int clen = (int)b2le32(scratch, xoff); - xoff += 4+clen; - - if(xoff > scratch.length) - xdie("string out of bounds"); - - String tag_raw = new String(scratch, xoff-clen, clen); - String[] tag_vec = tag_raw.split("=",2); - String tag_key = tag_vec[0].toUpperCase(); - - addTagEntry(tags, tag_key, tag_vec[1]); + long last_byte = offset + payload_len; + + // skip vendor string in format: [LEN][VENDOR_STRING] -> 4 = LEN = 32bit int + offset += 4 + raf2le32(fh, offset); + + // we can now read the number of comments in this file, we will also + // adjust offset to point to the value after this 32bit int + int comments = raf2le32(fh, offset); + offset += 4; + + for ( ; comments > 0; comments--) { + int comment_len = raf2le32(fh, offset); + offset += 4; + long can_read = last_byte - offset; // indicates the last byte of this page + int do_read = (int)(can_read > comment_len ? comment_len : can_read); // how much data is readable in this page + + if (do_read >= 3) { + int bsize = (do_read > MAX_COMMENT_SIZE ? MAX_COMMENT_SIZE : do_read); + byte[] data = new byte[bsize]; + fh.seek(offset); + fh.read(data); + String tag_raw = new String(data); + String[] tag_vec = tag_raw.split("=", 2); + String tag_key = tag_vec[0].toUpperCase(); + addTagEntry(tags, tag_key, tag_vec[1]); + } + + // set offset to begin of next tag (OR the end of this page!) + offset += do_read; + + // We hit the end of a stream + // this is most likely due to the fact that we cropped do_read to not cross + // the page boundary -> we must now calculate the position of the next tag + if (offset == last_byte) { + int partial_cruft = comment_len - do_read; // how many bytes we did not read + while(partial_cruft > 0) { + PageInfo pi = pp.parse_stream_page(fh, last_byte); + if (pi.header_len <1 || pi.payload_len < 1) + xdie("Data from callback doesnt make much sense"); + + offset += pi.header_len; // move position behind page header + last_byte = offset + pi.payload_len; // and adjust the last byte to pos + payload_size + + if (offset+partial_cruft < last_byte) { + offset += partial_cruft; // partial data ends in this block: just adjust the ofset + break; + } else { + // this page just contains data from the partial tag -> skip to next one + offset = last_byte; + partial_cruft -= pi.payload_len; + } + } + } } return tags; } - + public void addTagEntry(HashMap tags, String key, String value) { if(tags.containsKey(key)) { - ((Vector)tags.get(key)).add(value); // just add to existing vector + ((ArrayList)tags.get(key)).add(value); // just add to existing vector } else { - Vector vx = new Vector(); - vx.add(value); - tags.put(key, vx); + ArrayList l = new ArrayList<String>(); + l.add(value); + tags.put(key, l); } } |