rc: implement passing filter config with _filter parameter

docs/content/rc.md

@@ -303,6 +303,39 @@ setting the equivalent of `--buffer-size` in string or integer format.
 If you wish to check the `_config` assignment has worked properly then
 calling `options/local` will show what the value got set to.
 
+### Setting filter flags with _filter
+
+If you wish to set filters for the duration of an rc call only then
+pass in the `_filter` parameter.
+
+This should be in the same format as the `filter` key returned by
+[options/get](#options-get).
+
+For example, if you wished to run a sync with these flags
+
+    --max-size 1M --max-age 42s --include "a" --include "b"
+
+you would pass this parameter in your JSON blob.
+
+    "_filter":{"MaxSize":"1M", "IncludeRule":["a","b"], "MaxAge":"42s"}
+
+If using `rclone rc` this could be passed as
+
+    rclone rc ... _filter='{"MaxSize":"1M", "IncludeRule":["a","b"], "MaxAge":"42s"}'
+
+Any filter parameters you don't set will inherit the global defaults
+which were set with command line flags or environment variables.
+
+Note that it is possible to set some values as strings or integers -
+see [data types](/#data-types) for more info. Here is an example
+setting the equivalent of `--buffer-size` in string or integer format.
+
+    "_filter":{"MinSize": "42M"}
+    "_filter":{"MinSize": 44040192}
+
+If you wish to check the `_filter` assignment has worked properly then
+calling `options/local` will show what the value got set to.
+
 ### Assigning operations to groups with _group = value
 
 Each rc call has its own stats group for tracking its metrics. By default

fs/rc/jobs/job.go

@@ -13,6 +13,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/rclone/rclone/fs"
 	"github.com/rclone/rclone/fs/accounting"
+	"github.com/rclone/rclone/fs/filter"
 	"github.com/rclone/rclone/fs/rc"
 )
 
@@ -216,6 +217,27 @@ func getConfig(ctx context.Context, in rc.Params) (context.Context, error) {
 	return ctx, nil
 }
 
+// See if _filter is set and if so adjust ctx to include it
+func getFilter(ctx context.Context, in rc.Params) (context.Context, error) {
+	if _, ok := in["_filter"]; !ok {
+		return ctx, nil
+	}
+	// Copy of the current filter options
+	opt := filter.GetConfig(ctx).Opt
+	// Update the options from the parameter
+	err := in.GetStruct("_filter", &opt)
+	if err != nil {
+		return ctx, err
+	}
+	fi, err := filter.NewFilter(&opt)
+	if err != nil {
+		return ctx, err
+	}
+	ctx = filter.ReplaceConfig(ctx, fi)
+	delete(in, "_filter") // remove the parameter
+	return ctx, nil
+}
+
 // NewJob creates a Job and executes it, possibly in the background if _async is set
 func (jobs *Jobs) NewJob(ctx context.Context, fn rc.Func, in rc.Params) (job *Job, out rc.Params, err error) {
 	id := atomic.AddInt64(&jobID, 1)
@@ -231,6 +253,11 @@ func (jobs *Jobs) NewJob(ctx context.Context, fn rc.Func, in rc.Params) (job *Jo
 		return nil, nil, err
 	}
 
+	ctx, err = getFilter(ctx, in)
+	if err != nil {
+		return nil, nil, err
+	}
+
 	ctx, group, err := getGroup(ctx, in, id)
 	if err != nil {
 		return nil, nil, err

fs/rc/jobs/job_test.go

@@ -8,6 +8,8 @@ import (
 
 	"github.com/pkg/errors"
 	"github.com/rclone/rclone/fs"
+	"github.com/rclone/rclone/fs/accounting"
+	"github.com/rclone/rclone/fs/filter"
 	"github.com/rclone/rclone/fs/rc"
 	"github.com/rclone/rclone/fs/rc/rcflags"
 	"github.com/rclone/rclone/fstest/testy"
@@ -252,9 +254,11 @@ func TestExecuteJob(t *testing.T) {
 func TestExecuteJobWithConfig(t *testing.T) {
 	ctx := context.Background()
 	jobID = 0
+	called := false
 	jobFn := func(ctx context.Context, in rc.Params) (rc.Params, error) {
 		ci := fs.GetConfig(ctx)
 		assert.Equal(t, 42*fs.MebiByte, ci.BufferSize)
+		called = true
 		return nil, nil
 	}
 	_, _, err := NewJob(context.Background(), jobFn, rc.Params{
@@ -263,15 +267,59 @@ func TestExecuteJobWithConfig(t *testing.T) {
 		},
 	})
 	require.NoError(t, err)
+	assert.Equal(t, true, called)
+	// Retest with string parameter
 	jobID = 0
+	called = false
 	_, _, err = NewJob(ctx, jobFn, rc.Params{
 		"_config": `{"BufferSize": "42M"}`,
 	})
 	require.NoError(t, err)
+	assert.Equal(t, true, called)
+	// Check that wasn't the default
 	ci := fs.GetConfig(ctx)
 	assert.NotEqual(t, 42*fs.MebiByte, ci.BufferSize)
 }
 
+func TestExecuteJobWithFilter(t *testing.T) {
+	ctx := context.Background()
+	called := false
+	jobID = 0
+	jobFn := func(ctx context.Context, in rc.Params) (rc.Params, error) {
+		fi := filter.GetConfig(ctx)
+		assert.Equal(t, fs.SizeSuffix(1024), fi.Opt.MaxSize)
+		assert.Equal(t, []string{"a", "b", "c"}, fi.Opt.IncludeRule)
+		called = true
+		return nil, nil
+	}
+	_, _, err := NewJob(ctx, jobFn, rc.Params{
+		"_filter": rc.Params{
+			"IncludeRule": []string{"a", "b", "c"},
+			"MaxSize":     "1k",
+		},
+	})
+	require.NoError(t, err)
+	assert.Equal(t, true, called)
+}
+
+func TestExecuteJobWithGroup(t *testing.T) {
+	ctx := context.Background()
+	jobID = 0
+	called := false
+	jobFn := func(ctx context.Context, in rc.Params) (rc.Params, error) {
+		called = true
+		group, found := accounting.StatsGroupFromContext(ctx)
+		assert.Equal(t, true, found)
+		assert.Equal(t, "myparty", group)
+		return nil, nil
+	}
+	_, _, err := NewJob(ctx, jobFn, rc.Params{
+		"_group": "myparty",
+	})
+	require.NoError(t, err)
+	assert.Equal(t, true, called)
+}
+
 func TestExecuteJobErrorPropagation(t *testing.T) {
 	ctx := context.Background()
 	jobID = 0