Common stream reader interface for record filters (struct ZebraRecStream).

[idzebra-moved-to-github.git] / index / stream.c

diff --git a/index/stream.c b/index/stream.c
new file mode 100644 (file)
index 0000000..1ce54e4
--- /dev/null
+++ b/index/stream.c
@@ -0,0 +1,165 @@
+/* $Id: stream.c,v 1.1 2006-08-22 13:39:28 adam Exp $
+   Copyright (C) 1995-2006
+   Index Data ApS
+
+This file is part of the Zebra server.
+
+Zebra is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 2, or (at your option) any later
+version.
+
+Zebra is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+*/
+
+#include <stdio.h>
+#include <assert.h>
+
+#include <fcntl.h>
+#ifdef WIN32
+#include <io.h>
+#include <process.h>
+#endif
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include "index.h"
+
+struct zebra_mem_control {
+    off_t offset_end;
+    off_t record_int_pos;
+    const char *record_int_buf;
+    int record_int_len;
+};
+
+struct zebra_ext_control {
+    off_t offset_end;
+    off_t record_offset;
+    int fd;
+};
+
+static off_t zebra_mem_seek(struct ZebraRecStream *s, off_t offset)
+{
+    struct zebra_mem_control *fc = (struct zebra_mem_control *) s->fh;
+    return (off_t) (fc->record_int_pos = offset);
+}
+
+static off_t zebra_mem_tell(struct ZebraRecStream *s)
+{
+    struct zebra_mem_control *fc = (struct zebra_mem_control *) s->fh;
+    return (off_t) fc->record_int_pos;
+}
+
+static int zebra_mem_read(struct ZebraRecStream *s, char *buf, size_t count)
+{
+    struct zebra_mem_control *fc = (struct zebra_mem_control *) s->fh;
+    int l = fc->record_int_len - fc->record_int_pos;
+    if (l <= 0)
+        return 0;
+    l = (l < (int) count) ? l : (int) count;
+    memcpy (buf, fc->record_int_buf + fc->record_int_pos, l);
+    fc->record_int_pos += l;
+    return l;
+}
+
+static off_t zebra_mem_end(struct ZebraRecStream *s, off_t *offset)
+{
+    struct zebra_mem_control *fc = (struct zebra_mem_control *) s->fh;
+    if (offset)
+        fc->offset_end = *offset;
+    return fc->offset_end;
+}
+
+static void zebra_mem_destroy(struct ZebraRecStream *s)
+{
+    struct zebra_mem_control *fc = s->fh;
+    xfree(fc);
+}
+
+static int zebra_ext_read(struct ZebraRecStream *s, char *buf, size_t count)
+{
+    struct zebra_ext_control *fc = (struct zebra_ext_control *) s->fh;
+    return read(fc->fd, buf, count);
+}
+
+static off_t zebra_ext_seek(struct ZebraRecStream *s, off_t offset)
+{
+    struct zebra_ext_control *fc = (struct zebra_ext_control *) s->fh;
+    return lseek(fc->fd, offset + fc->record_offset, SEEK_SET);
+}
+
+static off_t zebra_ext_tell(struct ZebraRecStream *s)
+{
+    struct zebra_ext_control *fc = (struct zebra_ext_control *) s->fh;
+    return lseek(fc->fd, 0, SEEK_CUR) - fc->record_offset;
+}
+
+static void zebra_ext_destroy(struct ZebraRecStream *s)
+{
+    struct zebra_ext_control *fc = s->fh;
+    if (fc->fd != -1)
+        close(fc->fd);
+    xfree(fc);
+}
+
+static off_t zebra_ext_end(struct ZebraRecStream *s, off_t *offset)
+{
+    struct zebra_ext_control *fc = (struct zebra_ext_control *) s->fh;
+    if (offset)
+        fc->offset_end = *offset;
+    return fc->offset_end;
+}
+
+
+void zebra_create_stream_mem(struct ZebraRecStream *stream,
+                             const char *buf, size_t sz)
+{
+    struct zebra_mem_control *fc = xmalloc(sizeof(*fc));
+    fc->record_int_buf = buf;
+    fc->record_int_len = sz;
+    fc->record_int_pos = 0;
+    fc->offset_end = 0;
+
+    stream->fh = fc;
+    stream->readf = zebra_mem_read;
+    stream->seekf = zebra_mem_seek;
+    stream->tellf = zebra_mem_tell;
+    stream->endf = zebra_mem_end;
+    stream->destroy = zebra_mem_destroy;
+}
+
+void zebra_create_stream_fd(struct ZebraRecStream *stream,
+                            int fd, off_t start_offset)
+{
+    struct zebra_ext_control *fc = xmalloc(sizeof(*fc));
+
+    fc->fd = fd;
+    fc->record_offset = start_offset;
+    fc->offset_end = 0;
+    
+    stream->fh = fc;
+    stream->readf = zebra_ext_read;
+    stream->seekf = zebra_ext_seek;
+    stream->tellf = zebra_ext_tell;
+    stream->endf = zebra_ext_end;
+    stream->destroy = zebra_ext_destroy;
+    zebra_ext_seek(stream, 0);
+}
+
+/*
+ * Local variables:
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ * vim: shiftwidth=4 tabstop=8 expandtab
+ */
+