Pivot Operation

conformance/graphs/fhir.edges

@@ -0,0 +1,6 @@
+{"from":"patient_a", "to":"observation_a1", "label":"patient_observation"}
+{"from":"patient_a", "to":"observation_a2", "label":"patient_observation"}
+{"from":"patient_a", "to":"observation_a3", "label":"patient_observation"}
+{"from":"patient_b", "to":"observation_b1", "label":"patient_observation"}
+{"from":"patient_b", "to":"observation_b2", "label":"patient_observation"}
+{"from":"patient_b", "to":"observation_b3", "label":"patient_observation"}

conformance/graphs/fhir.vertices

@@ -0,0 +1,8 @@
+{"gid":"patient_a", "label":"Patient", "data":{"name":"Alice"}}
+{"gid":"patient_b", "label":"Patient", "data":{"name":"Bob"}}
+{"gid":"observation_a1", "label":"Observation", "data":{"key":"age", "value":36}}
+{"gid":"observation_a2", "label":"Observation", "data":{"key":"sex", "value":"Female"}}
+{"gid":"observation_a3", "label":"Observation", "data":{"key":"blood_pressure", "value":"111/78"}}
+{"gid":"observation_b1", "label":"Observation", "data":{"key":"age", "value":42}}
+{"gid":"observation_b2", "label":"Observation", "data":{"key":"sex", "value":"Male"}}
+{"gid":"observation_b3", "label":"Observation", "data":{"key":"blood_pressure", "value":"120/80"}}

conformance/tests/ot_aggregations.py

@@ -178,7 +178,7 @@ def test_traversal_gid_aggregation(man):
             return errors
 
         if planet_agg_map[row["key"]] != row["value"]:
-            errors.append("Incorrect bucket count returned: %s" % res)
+            errors.append("Incorrect bucket count returned: %s" % row)
 
     if count != 2:
         errors.append(

conformance/tests/ot_pivot.py

@@ -0,0 +1,14 @@
+from __future__ import absolute_import
+
+import gripql
+
+
+def test_pivot(man):
+    errors = []
+    G = man.setGraph("fhir")
+
+    for row in G.query().V().hasLabel("Patient").as_("a").out("patient_observation").pivot("$a._gid", "$.key", "$.value" ):
+        print(row)
+
+    return errors
+

engine/core/processors.go

@@ -3,6 +3,7 @@ package core
 import (
 	"bytes"
 	"context"
+	"encoding/json"
 	"fmt"
 	"math"
 	"reflect"
@@ -12,6 +13,7 @@ import (
 	"github.com/bmeg/grip/gdbi"
 	"github.com/bmeg/grip/gdbi/tpath"
 	"github.com/bmeg/grip/gripql"
+	"github.com/bmeg/grip/kvi"
 	"github.com/bmeg/grip/log"
 	"github.com/bmeg/grip/util/copy"
 	"github.com/influxdata/tdigest"
@@ -433,6 +435,73 @@ func (r *Render) Process(ctx context.Context, man gdbi.Manager, in gdbi.InPipe,
 
 ////////////////////////////////////////////////////////////////////////////////
 
+// Render takes current state and renders into requested structure
+type Pivot struct {
+	Stmt *gripql.PivotStep
+}
+
+// Process runs the pivot processor
+func (r *Pivot) Process(ctx context.Context, man gdbi.Manager, in gdbi.InPipe, out gdbi.OutPipe) context.Context {
+	go func() {
+		defer close(out)
+		kv := man.GetTempKV()
+		kv.BulkWrite(func(bl kvi.KVBulkWrite) error {
+			for t := range in {
+				if t.IsSignal() {
+					out <- t
+					continue
+				}
+				//fmt.Printf("Checking %#v\n", t.GetCurrent())
+				id := gdbi.TravelerPathLookup(t, r.Stmt.Id)
+				if idStr, ok := id.(string); ok {
+					field := gdbi.TravelerPathLookup(t, r.Stmt.Field)
+					if fieldStr, ok := field.(string); ok {
+						value := gdbi.TravelerPathLookup(t, r.Stmt.Value)
+						if v, err := json.Marshal(value); err == nil {
+							key := bytes.Join([][]byte{[]byte(idStr), []byte(fieldStr)}, []byte{0})
+							bl.Set(key, v)
+						}
+					}
+				}
+			}
+			return nil
+		})
+		kv.View(func(it kvi.KVIterator) error {
+			it.Seek([]byte{0})
+			lastKey := ""
+			curDict := map[string]any{}
+			for it.Seek([]byte{0}); it.Valid(); it.Next() {
+				tmp := bytes.Split(it.Key(), []byte{0})
+				curKey := string(tmp[0])
+				curField := string(tmp[1])
+				if lastKey == "" {
+					lastKey = curKey
+				}
+				var curData any
+				value, _ := it.Value()
+				json.Unmarshal(value, &curData)
+				if lastKey != curKey {
+					curDict["_id"] = curKey
+					out <- &gdbi.BaseTraveler{Render: curDict}
+					curDict = map[string]any{}
+					curDict[curField] = curData
+					lastKey = curKey
+				} else {
+					curDict[curField] = curData
+				}
+			}
+			if lastKey != "" {
+				curDict["_id"] = lastKey
+				out <- &gdbi.BaseTraveler{Render: curDict}
+			}
+			return nil
+		})
+	}()
+	return ctx
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
 // Path tells system to return path data
 type Path struct {
 	Template interface{} //this isn't really used yet.

engine/core/statement_compiler.go

@@ -198,6 +198,10 @@ func (sc *DefaultStmtCompiler) Render(stmt *gripql.GraphStatement_Render, ps *gd
 	return &Render{stmt.Render.AsInterface()}, nil
 }
 
+func (sc *DefaultStmtCompiler) Pivot(stmt *gripql.GraphStatement_Pivot, ps *gdbi.State) (gdbi.Processor, error) {
+	return &Pivot{stmt.Pivot}, nil
+}
+
 func (sc *DefaultStmtCompiler) Path(stmt *gripql.GraphStatement_Path, ps *gdbi.State) (gdbi.Processor, error) {
 	return &Path{stmt.Path.AsSlice()}, nil
 }

gdbi/pipeline.go

@@ -76,6 +76,8 @@ type StatementCompiler interface {
 	Select(gs *gripql.GraphStatement_Select, ps *State) (Processor, error)
 
 	Render(gs *gripql.GraphStatement_Render, ps *State) (Processor, error)
+	Pivot(gs *gripql.GraphStatement_Pivot, ps *State) (Processor, error)
+
 	Path(gs *gripql.GraphStatement_Path, ps *State) (Processor, error)
 	Unwind(gs *gripql.GraphStatement_Unwind, ps *State) (Processor, error)
 	Fields(gs *gripql.GraphStatement_Fields, ps *State) (Processor, error)

gdbi/statement_processor.go

@@ -205,6 +205,14 @@ func StatementProcessor(
 		ps.LastType = RenderData
 		return out, err
 
+	case *gripql.GraphStatement_Pivot:
+		if ps.LastType != VertexData && ps.LastType != EdgeData {
+			return nil, fmt.Errorf(`"pivot" statement is only valid for edge or vertex types not: %s`, ps.LastType.String())
+		}
+		out, err := sc.Pivot(stmt, ps)
+		ps.LastType = RenderData
+		return out, err
+
 	case *gripql.GraphStatement_Path:
 		if ps.LastType != VertexData && ps.LastType != EdgeData {
 			return nil, fmt.Errorf(`"path" statement is only valid for edge or vertex types not: %s`, ps.LastType.String())