Initial revision

1 files changed, 251 insertions, 0 deletions

diff --git a/rsync/job.c b/rsync/job.c
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+++ b/rsync/job.c
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+/*= -*- c-basic-offset: 4; indent-tabs-mode: nil; -*-
+ *
+ * librsync -- the library for network deltas
+ * $Id$
+ * 
+ * Copyright (C) 2000, 2001 by Martin Pool <mbp@samba.org>
+ * 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ * 
+ * This program 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
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+                              /*
+                               | The hard, lifeless I covered up the
+                               | warm, pulsing It; protecting and
+                               | sheltering.
+                               */
+
+/*
+ * job.c -- Generic state-machine interface.  The point of this is
+ * that we need to be able to suspend and resume processing at any
+ * point at which the buffers may block.  We could do that using
+ * setjmp or similar tricks, but this is probably simpler.
+ *
+ * TODO: We have a few functions to do with reading a netint, stashing
+ * it somewhere, then moving into a different state.  Is it worth
+ * writing generic functions fo r that, or would it be too confusing?
+ */
+
+
+#include <config_rsync.h>
+
+#include <stdlib.h>
+#include <assert.h>
+#include <stdio.h>
+
+#include "rsync.h"
+#include "stream.h"
+#include "util.h"
+#include "sumset.h"
+#include "job.h"
+#include "trace.h"
+
+
+static const int rs_job_tag = 20010225;
+
+static rs_result rs_job_work(rs_job_t *job, rs_buffers_t *buffers);
+
+
+rs_job_t * rs_job_new(char const *job_name, rs_result (*statefn)(rs_job_t *))
+{
+    rs_job_t *job;
+
+    job = rs_alloc_struct(rs_job_t);
+
+    job->job_name = job_name;
+    job->dogtag = rs_job_tag;
+    job->statefn = statefn;
+
+    job->stats.op = job_name;
+
+    rs_trace("start %s job", job_name);
+
+    return job;
+}
+
+
+void rs_job_check(rs_job_t *job)
+{
+    assert(job->dogtag == rs_job_tag);
+}
+
+
+rs_result rs_job_free(rs_job_t *job)
+{
+    rs_bzero(job, sizeof *job);
+    free(job);
+
+    return RS_DONE;
+}
+
+
+
+static rs_result rs_job_s_complete(rs_job_t *job)
+{
+    rs_fatal("should not be reached");
+    return RS_INTERNAL_ERROR;
+}
+
+
+static rs_result rs_job_complete(rs_job_t *job, rs_result result)
+{
+    rs_job_check(job);
+    
+    job->statefn = rs_job_s_complete;
+    job->final_result = result;
+
+    if (result != RS_DONE) {
+        rs_error("%s job failed: %s", job->job_name, rs_strerror(result));
+    } else {
+        rs_trace("%s job complete", job->job_name);
+    }
+
+    if (result == RS_DONE && !rs_tube_is_idle(job))
+        /* Processing is finished, but there is still some data
+         * waiting to get into the output buffer. */
+        return RS_BLOCKED;
+    else
+        return result;
+}
+
+
+/** 
+ * \brief Run a ::rs_job_t state machine until it blocks
+ * (::RS_BLOCKED), returns an error, or completes (::RS_COMPLETE).
+ *
+ * \return The ::rs_result that caused iteration to stop.
+ *
+ * \param ending True if there is no more data after what's in the
+ * input buffer.  The final block checksum will run across whatever's
+ * in there, without trying to accumulate anything else.
+ */
+rs_result rs_job_iter(rs_job_t *job, rs_buffers_t *buffers)
+{
+    rs_result       result;
+    rs_long_t       orig_in, orig_out;
+
+    orig_in  = buffers->avail_in;
+    orig_out = buffers->avail_out;
+
+    result = rs_job_work(job, buffers);
+
+    if (result == RS_BLOCKED  ||  result == RS_DONE) 
+        if ((orig_in == buffers->avail_in)  &&  (orig_out == buffers->avail_out)
+            && orig_in && orig_out) {
+            rs_log(RS_LOG_ERR, "internal error: job made no progress "
+                   "[orig_in=%.0f, orig_out=%.0f, final_in=%.0f, final_out=%.0f]",
+                   (double) orig_in, (double) orig_out, (double) buffers->avail_in,
+                   (double) buffers->avail_out);
+            return RS_INTERNAL_ERROR;
+        }
+
+    return result;
+}
+
+
+static rs_result
+rs_job_work(rs_job_t *job, rs_buffers_t *buffers)
+{
+    rs_result result;
+
+    rs_job_check(job);
+
+    if (!buffers) {
+        rs_error("NULL buffer passed to rs_job_iter");
+        return RS_PARAM_ERROR;
+    }
+    job->stream = buffers;
+    
+    while (1) {
+        result = rs_tube_catchup(job);
+        if (result == RS_BLOCKED)
+            return result;
+        else if (result != RS_DONE)
+            return rs_job_complete(job, result);
+
+        if (job->statefn == rs_job_s_complete) {
+            if (rs_tube_is_idle(job))
+                return RS_DONE;
+            else
+                return RS_BLOCKED;
+        } else {
+            result = job->statefn(job);
+            if (result == RS_RUNNING)
+                continue;
+            else if (result == RS_BLOCKED)
+                return result;
+            else
+                return rs_job_complete(job, result);
+        }
+    }
+
+    /* TODO: Before returning, check that we actually made some
+     * progress.  If not, and we're not returning an error, this is a
+     * bug. */
+}
+
+
+/**
+ * Return pointer to statistics accumulated about this job.
+ */
+const rs_stats_t *
+rs_job_statistics(rs_job_t *job)
+{
+    return &job->stats;
+}
+
+
+int
+rs_job_input_is_ending(rs_job_t *job)
+{
+    return job->stream->eof_in;
+}
+
+
+
+/**
+ * Actively process a job, by making callbacks to fill and empty the
+ * buffers until the job is done.
+ */
+rs_result
+rs_job_drive(rs_job_t *job, rs_buffers_t *buf,
+             rs_driven_cb in_cb, void *in_opaque,
+             rs_driven_cb out_cb, void *out_opaque)
+{
+    rs_result       result, iores;
+
+    rs_bzero(buf, sizeof *buf);
+
+    do {
+        if (!buf->eof_in && in_cb) {
+            iores = in_cb(job, buf, in_opaque);
+            if (iores != RS_DONE)
+                return iores;
+        }
+
+        result = rs_job_iter(job, buf);
+        if (result != RS_DONE  &&  result != RS_BLOCKED)
+            return result;
+
+        if (out_cb) {
+            iores = (out_cb)(job, buf, out_opaque);
+            if (iores != RS_DONE)
+                return iores;
+        }
+    } while (result != RS_DONE);
+
+    return result;
+}
+