Improve datalog reader API to be more pythonic

- Add bulk of wpilib printlog example to examples

Author: virtuald

examples/printlog.py

@@ -1,7 +1,11 @@
 #!/usr/bin/env python3
+#
+# Copyright (c) FIRST and other WPILib contributors.
+# Open Source Software; you can modify and/or share it under the terms of
+# the WPILib BSD license file in the root directory of this project.
 
 import argparse
-import pathlib
+import datetime
 
 from wpiutil.log import DataLogReader
 
@@ -11,8 +15,78 @@
     args = parser.parse_args()
 
     reader = DataLogReader(args.infile)
+
+    entries = {}
     for record in reader:
+        timestamp = record.getTimestamp() / 1000000
         if record.isStart():
-            print(record.getStartData())
+            try:
+                data = record.getStartData()
+                print(f"{data} [{timestamp}]")
+                if data.entry in entries:
+                    print("...DUPLICATE entry ID, overriding")
+                entries[data.entry] = data
+            except TypeError as e:
+                print("Start(INVALID)")
+        elif record.isFinish():
+            try:
+                entry = record.getFinishEntry()
+                print(f"Finish({entry}) [{timestamp}]")
+                if entry not in entries:
+                    print("...ID not found")
+                else:
+                    del entries[entry]
+            except TypeError as e:
+                print("Finish(INVALID)")
+        elif record.isSetMetadata():
+            try:
+                data = record.getSetMetadataData()
+                print(f"{data} [{timestamp}]")
+                if data.entry not in entries:
+                    print("...ID not found")
+            except TypeError as e:
+                print("SetMetadata(INVALID)")
+        elif record.isControl():
+            print("Unrecognized control record")
         else:
-            print(record.getBoolean())
+            print(f"Data({record.getEntry()}, size={record.getSize()}) ", end="")
+            entry = entries.get(record.getEntry(), None)
+            if entry is None:
+                print("<ID not found>")
+                continue
+            print(f"<name='{entry.name}', type='{entry.type}'> [{timestamp}]")
+
+            try:
+                # handle systemTime specially
+                if entry.name == "systemTime" and entry.type == "int64":
+                    dt = datetime.fromtimestamp(record.getInteger() / 1000000)
+                    print("  {:%Y-%m-%d %H:%M:%S.%f}".format(dt))
+                    continue
+
+                if entry.type == "double":
+                    print(f"  {record.getDouble()}")
+                elif entry.type == "int64":
+                    print(f"  {record.getInteger()}")
+                elif entry.type == "string" or entry.type == "json":
+                    print(f"  '{record.getString()}'")
+                elif entry.type == "boolean":
+                    print(f"  {record.getBoolean()}")
+                elif entry.type == "boolean[]":
+                    arr = record.getBooleanArray()
+                    print(f"  {arr}")
+                elif entry.type == "double[]":
+                    arr = record.getDoubleArray()
+                    print(f"  {arr}")
+                elif entry.type == "float[]":
+                    arr = record.getFloatArray()
+                    print(f"  {arr}")
+                elif entry.type == "int64[]":
+                    arr = record.getIntegerArray()
+                    print(f"  {arr}")
+                elif entry.type == "string[]":
+                    arr = record.getStringArray()
+                    print(f"  {arr}")
+                elif entry.type == "raw":
+                    print(f"  {record.getRaw()}")
+            except TypeError as e:
+                print("  invalid", e)

examples/writelog.py

@@ -3,7 +3,7 @@
 import argparse
 import pathlib
 
-from wpiutil.log import DataLog, BooleanLogEntry
+from wpiutil.log import DataLog, BooleanLogEntry, StringArrayLogEntry, RawLogEntry
 
 
 if __name__ == "__main__":
@@ -20,3 +20,11 @@
     bools = BooleanLogEntry(datalog, "/bools")
     bools.append(True)
     bools.append(False)
+
+    strings = StringArrayLogEntry(datalog, "/strings")
+    strings.append(["a", "b", "c"])
+    strings.append(["d", "e", "f"])
+
+    raw = RawLogEntry(datalog, "/raws")
+    raw.append(b'\x01\x02\x03')
+    raw.append(b'\x04\x05\x06')