Mercurial Hosting > luan
changeset 1489:fe237d72b234
improve BufferedInputStream
author | Franklin Schmidt <fschmidt@gmail.com> |
---|---|
date | Sat, 02 May 2020 16:28:24 -0600 |
parents | af55cfad6e12 |
children | 9a2a2181a58f |
files | src/goodjava/io/BufferedInputStream.java |
diffstat | 1 files changed, 36 insertions(+), 20 deletions(-) [+] |
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--- a/src/goodjava/io/BufferedInputStream.java Sat May 02 15:38:48 2020 -0600 +++ b/src/goodjava/io/BufferedInputStream.java Sat May 02 16:28:24 2020 -0600 @@ -120,23 +120,34 @@ * Read characters into a portion of an array, reading from the underlying * stream at most once if necessary. */ - public synchronized int read(byte[] b, int off, int len) throws IOException { + private int read1(byte[] b, int off, int len) throws IOException { + int cnt = 0; int avail = count - pos; - if (avail <= 0) { - /* If the requested length is at least as large as the buffer, do not bother to copy the - bytes into the local buffer. In this way buffered streams will - cascade harmlessly. */ - if (len >= buf.length) { - return super.read(b, off, len); - } - fill(); - avail = count - pos; - if (avail <= 0) return -1; + if( avail > 0 ) { + cnt = (avail < len) ? avail : len; + System.arraycopy(buf, pos, b, off, cnt); + pos += cnt; + len -= cnt; + if( len == 0 ) + return cnt; + off += cnt; + } + if (len >= buf.length) { + return cnt + Math.max( 0, super.read(b, off, len) ); } - int cnt = (avail < len) ? avail : len; - System.arraycopy(buf, pos, b, off, cnt); - pos += cnt; - return cnt; + fill(); + if (count <= 0) + return cnt; + System.arraycopy(buf, 0, b, off, len); + pos += len; + return cnt + len; + } + + public synchronized int read(byte[] b, int off, int len) throws IOException { + if( len == 0 ) + return 0; + int n = read1(b,off,len); + return n==0 ? -1 : n; } /** @@ -149,13 +160,18 @@ * I/O error occurs. */ public synchronized long skip(long n) throws IOException { + if( n <= 0 ) + return 0; + long skipped = 0; long avail = count - pos; - if (avail <= 0) { - return super.skip(n); + if( avail > 0 ) { + skipped = (avail < n) ? avail : n; + pos += skipped; + n -= skipped; + if( n == 0 ) + return skipped; } - long skipped = (avail < n) ? avail : n; - pos += skipped; - return skipped; + return skipped + super.skip(n); } /**