Python library can read metadata from bgcode files

pybgcode/pybgcode.cpp

@@ -2,6 +2,7 @@
 #include <cerrno>
 #include <cstring>
 #include <pybind11/pybind11.h>
+#include <pybind11/stl.h>
 
 #include <boost/nowide/cstdio.hpp>
 
@@ -154,7 +155,7 @@ PYBIND11_MODULE(MODULE_NAME, m) {
     py::enum_<core::EBlockType>(m, "EBlockType")
         .value("FileMetadata", core::EBlockType::FileMetadata)
         .value("GCode", core::EBlockType::GCode)
-        .value("SlicerMetadata,", core::EBlockType::SlicerMetadata)
+        .value("SlicerMetadata", core::EBlockType::SlicerMetadata)
         .value("PrinterMetadata", core::EBlockType::PrinterMetadata)
         .value("PrintMetadata", core::EBlockType::PrintMetadata)
         .value("Thumbnail", core::EBlockType::Thumbnail);

pybgcode/pybgcode/__init__.py

@@ -1,5 +1,6 @@
 """Prusa Block & Binary G-code reader / writer / converter"""
 # pylint: disable=redefined-builtin
+from typing import Type, Union
 from ._bgcode import (  # type: ignore
     BlockHeader,
     CompressionType,
@@ -8,6 +9,10 @@
     EThumbnailFormat,
     FileHeader,
     FILEWrapper,
+    PrintMetadataBlock,
+    PrinterMetadataBlock,
+    SlicerMetadataBlock,
+    FileMetadataBlock,
     ThumbnailBlock,
     close,
     from_ascii_to_binary,
@@ -31,6 +36,9 @@
         "EResult",
         "EThumbnailFormat",
         "FileHeader",
+        "FileMetadataBlock",
+        "PrintMetadataBlock",
+        "PrinterMetadataBlock",
         "ThumbnailBlock",
         "close",
         "from_ascii_to_binary",
@@ -51,30 +59,78 @@ def __init__(self, res: EResult):
         super().__init__(translate_result(res))
 
 
-def read_thumbnails(gcodefile: FILEWrapper):
-    """Read thumbnails from binary gcode file."""
+def get_header(gcodefile: FILEWrapper):
     assert is_open(gcodefile)
     rewind(gcodefile)
-
     header = FileHeader()
     res = read_header(gcodefile, header)
     if res != EResult.Success:
         raise ResultError(res)
+    return res, header
 
+def get_block_header(gcodefile: FILEWrapper, header: FileHeader,
+                     block_type: int):
     block = BlockHeader()
+    res = read_next_block_header(gcodefile, header, block, block_type)
+    if res != EResult.Success:
+        return None
+    return block
+
+def get_metadata(gcodefile: FILEWrapper, header: FileHeader,
+                 block_header: BlockHeader,
+                 metadata_block_class: Union[Type[PrinterMetadataBlock],
+                                             Type[PrintMetadataBlock],
+                                             Type[FileMetadataBlock]]):
+    metadata_block = metadata_block_class()
+    res = metadata_block.read_data(gcodefile, header, block_header)
+    if res != EResult.Success:
+        raise ResultError(res)
+    return dict(metadata_block.raw_data) if metadata_block else metadata_block
+
+def read_thumbnails(gcodefile: FILEWrapper):
+    """Read thumbnails from binary gcode file."""
+    res, header = get_header(gcodefile)
     thumbnails = []
+
     while res == EResult.Success:
-        res = read_next_block_header(gcodefile, header, block,
-                                     EBlockType.Thumbnail)
-        if res != EResult.Success:
+        block_header = get_block_header(gcodefile, header,
+                                        EBlockType.Thumbnail)
+        if not block_header:
             break
 
         thumbnail_block = ThumbnailBlock()
-        res = thumbnail_block.read_data(gcodefile, header, block)
+        res = thumbnail_block.read_data(gcodefile, header, block_header)
         if res != EResult.Success:
             raise ResultError(res)
 
         thumbnails.append({"meta": thumbnail_block.params,
                            "bytes": thumbnail_block.data()})
 
     return thumbnails
+
+def read_metadata(gcodefile: FILEWrapper, type: str = 'printer'):
+    """Read metadata from binary gcode file.
+    Possible variants for metadata type are 'file', 'print', 'printer'
+    and 'slicer' with 'printer' as a default."""
+
+    _, header = get_header(gcodefile)
+
+    if type == 'file':
+        block_type = EBlockType.FileMetadata
+        metadata_block_class = FileMetadataBlock
+    elif type == 'print':
+        block_type = EBlockType.PrintMetadata
+        metadata_block_class = PrintMetadataBlock
+    elif type == 'slicer':
+        block_type = EBlockType.SlicerMetadata
+        metadata_block_class = SlicerMetadataBlock
+    else:
+        block_type = EBlockType.PrinterMetadata
+        metadata_block_class = PrinterMetadataBlock
+
+    block_header = get_block_header(gcodefile, header, block_type)
+    if not block_header:
+        return None
+
+    return get_metadata(gcodefile, header, block_header, metadata_block_class)
+

pybgcode/tests/test_convert.py

@@ -8,6 +8,7 @@
     EResult,
     EThumbnailFormat,
     read_thumbnails,
+    read_metadata
 )
 
 # pylint: disable=missing-function-docstring
@@ -16,6 +17,26 @@
 TEST_BGCODE = "test.bgcode"
 TEST_THUMBNAILS = 2
 
+TEST_PRINTER_METADATA = {'printer_model': 'MINI', 'filament_type': 'PETG',
+                         'nozzle_diameter': '0.4', 'bed_temperature': '90',
+                         'brim_width': '0', 'fill_density': '15%',
+                         'layer_height': '0.15', 'temperature': '240',
+                         'ironing': '0', 'support_material': '0',
+                         'max_layer_z': '18.05', 'extruder_colour': '""',
+                         'filament used [mm]': '986.61',
+                         'filament used [cm3]': '2.37',
+                         'filament used [g]': '3.01', 'filament cost': '0.08',
+                         'estimated printing time (normal mode)': '32m 6s'}
+TEST_FILE_METADATA = {'Producer': 'PrusaSlicer 2.6.0'}
+TEST_PRINT_METADATA = {
+    'filament used [mm]': '986.61', 'filament used [cm3]': '2.37',
+    'filament used [g]': '3.01', 'filament cost': '0.08',
+    'total filament used [g]': '3.01', 'total filament cost': '0.08',
+    'estimated printing time (normal mode)': '32m 6s',
+    'estimated first layer printing time (normal mode)': '1m 8s'}
+TEST_LEN_SLICER_METADATA = 302
+
+
 
 def get_thumbnail_extension(format_id):
     ret = "unknown"
@@ -53,6 +74,14 @@ def test_main():
     thumb_f = pybgcode.open(TEST_BGCODE, "rb")
     thumbnails = read_thumbnails(thumb_f)
     assert len(thumbnails) == TEST_THUMBNAILS
+    printer_metadata = read_metadata(thumb_f)
+    assert printer_metadata == TEST_PRINTER_METADATA
+    file_metadata = read_metadata(thumb_f, 'file')
+    assert file_metadata == TEST_FILE_METADATA
+    print_metadata = read_metadata(thumb_f, 'print')
+    assert print_metadata == TEST_PRINT_METADATA
+    slicer_metadata = read_metadata(thumb_f, 'slicer')
+    assert len(slicer_metadata) == TEST_LEN_SLICER_METADATA
     pybgcode.close(thumb_f)
 
     # write thumbnails to png files