chore: 添加虚拟环境到仓库

- 添加 backend_service/venv 虚拟环境
- 包含所有Python依赖包
- 注意：虚拟环境约393MB，包含12655个文件

backend_service/venv/lib/python3.13/site-packages/flatbuffers/__init__.py

@@ -0,0 +1,19 @@
+# Copyright 2014 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from . import util
+from ._version import __version__
+from .builder import Builder
+from .compat import range_func as compat_range
+from .table import Table

backend_service/venv/lib/python3.13/site-packages/flatbuffers/_version.py

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+# Copyright 2019 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Placeholder, to be updated during the release process
+# by the setup.py
+__version__ = "25.9.23"

backend_service/venv/lib/python3.13/site-packages/flatbuffers/builder.py

@@ -0,0 +1,870 @@
+# Copyright 2014 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import warnings
+
+from . import compat
+from . import encode
+from . import number_types as N
+from . import packer
+from .compat import memoryview_type
+from .compat import NumpyRequiredForThisFeature, import_numpy
+from .compat import range_func
+from .number_types import (SOffsetTFlags, UOffsetTFlags, VOffsetTFlags)
+
+np = import_numpy()
+## @file
+## @addtogroup flatbuffers_python_api
+## @{
+
+
+## @cond FLATBUFFERS_INTERNAL
+class OffsetArithmeticError(RuntimeError):
+  """Error caused by an Offset arithmetic error.
+
+  Probably caused by bad writing of fields. This is considered an unreachable
+  situation in normal circumstances.
+  """
+
+  pass
+
+
+class IsNotNestedError(RuntimeError):
+  """Error caused by using a Builder to write Object data when not inside
+
+  an Object.
+  """
+
+  pass
+
+
+class IsNestedError(RuntimeError):
+  """Error caused by using a Builder to begin an Object when an Object is
+
+  already being built.
+  """
+
+  pass
+
+
+class StructIsNotInlineError(RuntimeError):
+  """Error caused by using a Builder to write a Struct at a location that
+
+  is not the current Offset.
+  """
+
+  pass
+
+
+class BuilderSizeError(RuntimeError):
+  """Error caused by causing a Builder to exceed the hardcoded limit of 2
+
+  gigabytes.
+  """
+
+  pass
+
+
+class BuilderNotFinishedError(RuntimeError):
+  """Error caused by not calling `Finish` before calling `Output`."""
+
+  pass
+
+
+class EndVectorLengthMismatched(RuntimeError):
+  """The number of elements passed to EndVector does not match the number
+
+  specified in StartVector.
+  """
+
+  pass
+
+
+# VtableMetadataFields is the count of metadata fields in each vtable.
+VtableMetadataFields = 2
+## @endcond
+
+
+class Builder(object):
+  """A Builder is used to construct one or more FlatBuffers.
+
+  Typically, Builder objects will be used from code generated by the `flatc`
+  compiler.
+
+  A Builder constructs byte buffers in a last-first manner for simplicity and
+  performance during reading.
+
+  Internally, a Builder is a state machine for creating FlatBuffer objects.
+
+  It holds the following internal state:
+      - Bytes: an array of bytes.
+      - current_vtable: a list of integers.
+      - vtables: a hash of vtable entries.
+
+  Attributes:
+    Bytes: The internal `bytearray` for the Builder.
+    finished: A boolean determining if the Builder has been finalized.
+  """
+
+  ## @cond FLATBUFFERS_INTENRAL
+  __slots__ = (
+      "Bytes",
+      "current_vtable",
+      "head",
+      "minalign",
+      "objectEnd",
+      "vtables",
+      "nested",
+      "forceDefaults",
+      "finished",
+      "vectorNumElems",
+      "sharedStrings",
+  )
+
+  """Maximum buffer size constant, in bytes.
+
+    Builder will never allow it's buffer grow over this size.
+    Currently equals 2Gb.
+    """
+  MAX_BUFFER_SIZE = 2**31
+  ## @endcond
+
+  def __init__(self, initialSize=1024):
+    """Initializes a Builder of size `initial_size`.
+
+    The internal buffer is grown as needed.
+    """
+
+    if not (0 <= initialSize <= Builder.MAX_BUFFER_SIZE):
+      msg = "flatbuffers: Cannot create Builder larger than 2 gigabytes."
+      raise BuilderSizeError(msg)
+
+    self.Bytes = bytearray(initialSize)
+    ## @cond FLATBUFFERS_INTERNAL
+    self.current_vtable = None
+    self.head = UOffsetTFlags.py_type(initialSize)
+    self.minalign = 1
+    self.objectEnd = None
+    self.vtables = {}
+    self.nested = False
+    self.forceDefaults = False
+    self.sharedStrings = {}
+    ## @endcond
+    self.finished = False
+
+  def Clear(self) -> None:
+    ## @cond FLATBUFFERS_INTERNAL
+    self.current_vtable = None
+    self.head = UOffsetTFlags.py_type(len(self.Bytes))
+    self.minalign = 1
+    self.objectEnd = None
+    self.vtables = {}
+    self.nested = False
+    self.forceDefaults = False
+    self.sharedStrings = {}
+    self.vectorNumElems = None
+    ## @endcond
+    self.finished = False
+
+  def Output(self):
+    """Return the portion of the buffer that has been used for writing data.
+
+    This is the typical way to access the FlatBuffer data inside the
+    builder. If you try to access `Builder.Bytes` directly, you would need
+    to manually index it with `Head()`, since the buffer is constructed
+    backwards.
+
+    It raises BuilderNotFinishedError if the buffer has not been finished
+    with `Finish`.
+    """
+
+    if not self.finished:
+      raise BuilderNotFinishedError()
+
+    return self.Bytes[self.Head() :]
+
+  ## @cond FLATBUFFERS_INTERNAL
+  def StartObject(self, numfields):
+    """StartObject initializes bookkeeping for writing a new object."""
+
+    self.assertNotNested()
+
+    # use 32-bit offsets so that arithmetic doesn't overflow.
+    self.current_vtable = [0 for _ in range_func(numfields)]
+    self.objectEnd = self.Offset()
+    self.nested = True
+
+  def WriteVtable(self):
+    """WriteVtable serializes the vtable for the current object, if needed.
+
+    Before writing out the vtable, this checks pre-existing vtables for
+    equality to this one. If an equal vtable is found, point the object to
+    the existing vtable and return.
+
+    Because vtable values are sensitive to alignment of object data, not
+    all logically-equal vtables will be deduplicated.
+
+    A vtable has the following format:
+      <VOffsetT: size of the vtable in bytes, including this value>
+      <VOffsetT: size of the object in bytes, including the vtable offset>
+      <VOffsetT: offset for a field> * N, where N is the number of fields
+                 in the schema for this type. Includes deprecated fields.
+    Thus, a vtable is made of 2 + N elements, each VOffsetT bytes wide.
+
+    An object has the following format:
+      <SOffsetT: offset to this object's vtable (may be negative)>
+      <byte: data>+
+    """
+
+    # Prepend a zero scalar to the object. Later in this function we'll
+    # write an offset here that points to the object's vtable:
+    self.PrependSOffsetTRelative(0)
+
+    objectOffset = self.Offset()
+
+    vtKey = []
+    trim = True
+    for elem in reversed(self.current_vtable):
+      if elem == 0:
+        if trim:
+          continue
+      else:
+        elem = objectOffset - elem
+        trim = False
+
+      vtKey.append(elem)
+
+    vtKey = tuple(vtKey)
+    vt2Offset = self.vtables.get(vtKey)
+    if vt2Offset is None:
+      # Did not find a vtable, so write this one to the buffer.
+
+      # Write out the current vtable in reverse , because
+      # serialization occurs in last-first order:
+      i = len(self.current_vtable) - 1
+      trailing = 0
+      trim = True
+      while i >= 0:
+        off = 0
+        elem = self.current_vtable[i]
+        i -= 1
+
+        if elem == 0:
+          if trim:
+            trailing += 1
+            continue
+        else:
+          # Forward reference to field;
+          # use 32bit number to ensure no overflow:
+          off = objectOffset - elem
+          trim = False
+
+        self.PrependVOffsetT(off)
+
+      # The two metadata fields are written last.
+
+      # First, store the object bytesize:
+      objectSize = UOffsetTFlags.py_type(objectOffset - self.objectEnd)
+      self.PrependVOffsetT(VOffsetTFlags.py_type(objectSize))
+
+      # Second, store the vtable bytesize:
+      vBytes = len(self.current_vtable) - trailing + VtableMetadataFields
+      vBytes *= N.VOffsetTFlags.bytewidth
+      self.PrependVOffsetT(VOffsetTFlags.py_type(vBytes))
+
+      # Next, write the offset to the new vtable in the
+      # already-allocated SOffsetT at the beginning of this object:
+      objectStart = SOffsetTFlags.py_type(len(self.Bytes) - objectOffset)
+      encode.Write(
+          packer.soffset,
+          self.Bytes,
+          objectStart,
+          SOffsetTFlags.py_type(self.Offset() - objectOffset),
+      )
+
+      # Finally, store this vtable in memory for future
+      # deduplication:
+      self.vtables[vtKey] = self.Offset()
+    else:
+      # Found a duplicate vtable.
+      objectStart = SOffsetTFlags.py_type(len(self.Bytes) - objectOffset)
+      self.head = UOffsetTFlags.py_type(objectStart)
+
+      # Write the offset to the found vtable in the
+      # already-allocated SOffsetT at the beginning of this object:
+      encode.Write(
+          packer.soffset,
+          self.Bytes,
+          self.Head(),
+          SOffsetTFlags.py_type(vt2Offset - objectOffset),
+      )
+
+    self.current_vtable = None
+    return objectOffset
+
+  def EndObject(self):
+    """EndObject writes data necessary to finish object construction."""
+    self.assertNested()
+    self.nested = False
+    return self.WriteVtable()
+
+  def growByteBuffer(self):
+    """Doubles the size of the byteslice, and copies the old data towards
+
+    the end of the new buffer (since we build the buffer backwards).
+    """
+    if len(self.Bytes) == Builder.MAX_BUFFER_SIZE:
+      msg = "flatbuffers: cannot grow buffer beyond 2 gigabytes"
+      raise BuilderSizeError(msg)
+
+    newSize = min(len(self.Bytes) * 2, Builder.MAX_BUFFER_SIZE)
+    if newSize == 0:
+      newSize = 1
+    bytes2 = bytearray(newSize)
+    bytes2[newSize - len(self.Bytes) :] = self.Bytes
+    self.Bytes = bytes2
+
+  ## @endcond
+
+  def Head(self):
+    """Get the start of useful data in the underlying byte buffer.
+
+    Note: unlike other functions, this value is interpreted as from the
+    left.
+    """
+    ## @cond FLATBUFFERS_INTERNAL
+    return self.head
+    ## @endcond
+
+  ## @cond FLATBUFFERS_INTERNAL
+  def Offset(self):
+    """Offset relative to the end of the buffer."""
+    return UOffsetTFlags.py_type(len(self.Bytes) - self.Head())
+
+  def Pad(self, n):
+    """Pad places zeros at the current offset."""
+    for i in range_func(n):
+      self.Place(0, N.Uint8Flags)
+
+  def Prep(self, size, additionalBytes):
+    """Prep prepares to write an element of `size` after `additional_bytes`
+
+    have been written, e.g. if you write a string, you need to align
+    such the int length field is aligned to SizeInt32, and the string
+    data follows it directly.
+    If all you need to do is align, `additionalBytes` will be 0.
+    """
+
+    # Track the biggest thing we've ever aligned to.
+    if size > self.minalign:
+      self.minalign = size
+
+    # Find the amount of alignment needed such that `size` is properly
+    # aligned after `additionalBytes`:
+    alignSize = (~(len(self.Bytes) - self.Head() + additionalBytes)) + 1
+    alignSize &= size - 1
+
+    # Reallocate the buffer if needed:
+    while self.Head() < alignSize + size + additionalBytes:
+      oldBufSize = len(self.Bytes)
+      self.growByteBuffer()
+      updated_head = self.head + len(self.Bytes) - oldBufSize
+      self.head = UOffsetTFlags.py_type(updated_head)
+    self.Pad(alignSize)
+
+  def PrependSOffsetTRelative(self, off):
+    """PrependSOffsetTRelative prepends an SOffsetT, relative to where it
+
+    will be written.
+    """
+
+    # Ensure alignment is already done:
+    self.Prep(N.SOffsetTFlags.bytewidth, 0)
+    if not (off <= self.Offset()):
+      msg = "flatbuffers: Offset arithmetic error."
+      raise OffsetArithmeticError(msg)
+    off2 = self.Offset() - off + N.SOffsetTFlags.bytewidth
+    self.PlaceSOffsetT(off2)
+
+  ## @endcond
+
+  def PrependUOffsetTRelative(self, off):
+    """Prepends an unsigned offset into vector data, relative to where it
+
+    will be written.
+    """
+
+    # Ensure alignment is already done:
+    self.Prep(N.UOffsetTFlags.bytewidth, 0)
+    if not (off <= self.Offset()):
+      msg = "flatbuffers: Offset arithmetic error."
+      raise OffsetArithmeticError(msg)
+    off2 = self.Offset() - off + N.UOffsetTFlags.bytewidth
+    self.PlaceUOffsetT(off2)
+
+  ## @cond FLATBUFFERS_INTERNAL
+  def StartVector(self, elemSize, numElems, alignment):
+    """StartVector initializes bookkeeping for writing a new vector.
+
+    A vector has the following format:
+      - <UOffsetT: number of elements in this vector>
+      - <T: data>+, where T is the type of elements of this vector.
+    """
+
+    self.assertNotNested()
+    self.nested = True
+    self.vectorNumElems = numElems
+    self.Prep(N.Uint32Flags.bytewidth, elemSize * numElems)
+    self.Prep(alignment, elemSize * numElems)  # In case alignment > int.
+    return self.Offset()
+
+  ## @endcond
+
+  def EndVector(self, numElems=None):
+    """EndVector writes data necessary to finish vector construction."""
+
+    self.assertNested()
+    ## @cond FLATBUFFERS_INTERNAL
+    self.nested = False
+    ## @endcond
+
+    if numElems:
+      warnings.warn("numElems is deprecated.", DeprecationWarning, stacklevel=2)
+      if numElems != self.vectorNumElems:
+        raise EndVectorLengthMismatched()
+
+    # we already made space for this, so write without PrependUint32
+    self.PlaceUOffsetT(self.vectorNumElems)
+    self.vectorNumElems = None
+    return self.Offset()
+
+  def CreateSharedString(self, s, encoding="utf-8", errors="strict"):
+    """CreateSharedString checks if the string is already written to the buffer
+
+    before calling CreateString.
+    """
+
+    if s in self.sharedStrings:
+      return self.sharedStrings[s]
+
+    off = self.CreateString(s, encoding, errors)
+    self.sharedStrings[s] = off
+
+    return off
+
+  def CreateString(self, s, encoding="utf-8", errors="strict"):
+    """CreateString writes a null-terminated byte string as a vector."""
+
+    self.assertNotNested()
+    ## @cond FLATBUFFERS_INTERNAL
+    self.nested = True
+    ## @endcond
+
+    if isinstance(s, compat.string_types):
+      x = s.encode(encoding, errors)
+    elif isinstance(s, compat.binary_types):
+      x = s
+    else:
+      raise TypeError("non-string passed to CreateString")
+
+    self.Prep(N.UOffsetTFlags.bytewidth, (len(x) + 1) * N.Uint8Flags.bytewidth)
+    self.Place(0, N.Uint8Flags)
+
+    l = UOffsetTFlags.py_type(len(s))
+    ## @cond FLATBUFFERS_INTERNAL
+    self.head = UOffsetTFlags.py_type(self.Head() - l)
+    ## @endcond
+    self.Bytes[self.Head() : self.Head() + l] = x
+
+    self.vectorNumElems = len(x)
+    return self.EndVector()
+
+  def CreateByteVector(self, x):
+    """CreateString writes a byte vector."""
+
+    self.assertNotNested()
+    ## @cond FLATBUFFERS_INTERNAL
+    self.nested = True
+    ## @endcond
+
+    if not isinstance(x, compat.binary_types):
+      raise TypeError("non-byte vector passed to CreateByteVector")
+
+    self.Prep(N.UOffsetTFlags.bytewidth, len(x) * N.Uint8Flags.bytewidth)
+
+    l = UOffsetTFlags.py_type(len(x))
+    ## @cond FLATBUFFERS_INTERNAL
+    self.head = UOffsetTFlags.py_type(self.Head() - l)
+    ## @endcond
+    self.Bytes[self.Head() : self.Head() + l] = x
+
+    self.vectorNumElems = len(x)
+    return self.EndVector()
+
+  def CreateNumpyVector(self, x):
+    """CreateNumpyVector writes a numpy array into the buffer."""
+
+    if np is None:
+      # Numpy is required for this feature
+      raise NumpyRequiredForThisFeature("Numpy was not found.")
+
+    if not isinstance(x, np.ndarray):
+      raise TypeError("non-numpy-ndarray passed to CreateNumpyVector")
+
+    if x.dtype.kind not in ["b", "i", "u", "f"]:
+      raise TypeError("numpy-ndarray holds elements of unsupported datatype")
+
+    if x.ndim > 1:
+      raise TypeError("multidimensional-ndarray passed to CreateNumpyVector")
+
+    self.StartVector(x.itemsize, x.size, x.dtype.alignment)
+
+    # Ensure little endian byte ordering
+    if x.dtype.str[0] == "<":
+      x_lend = x
+    else:
+      x_lend = x.byteswap(inplace=False)
+
+    # Calculate total length
+    l = UOffsetTFlags.py_type(x_lend.itemsize * x_lend.size)
+    ## @cond FLATBUFFERS_INTERNAL
+    self.head = UOffsetTFlags.py_type(self.Head() - l)
+    ## @endcond
+
+    # tobytes ensures c_contiguous ordering
+    self.Bytes[self.Head() : self.Head() + l] = x_lend.tobytes(order="C")
+
+    self.vectorNumElems = x.size
+    return self.EndVector()
+
+  ## @cond FLATBUFFERS_INTERNAL
+  def assertNested(self):
+    """Check that we are in the process of building an object."""
+
+    if not self.nested:
+      raise IsNotNestedError()
+
+  def assertNotNested(self):
+    """Check that no other objects are being built while making this object.
+
+    If not, raise an exception.
+    """
+
+    if self.nested:
+      raise IsNestedError()
+
+  def assertStructIsInline(self, obj):
+    """Structs are always stored inline, so need to be created right
+
+    where they are used. You'll get this error if you created it
+    elsewhere.
+    """
+
+    N.enforce_number(obj, N.UOffsetTFlags)
+    if obj != self.Offset():
+      msg = (
+          "flatbuffers: Tried to write a Struct at an Offset that "
+          "is different from the current Offset of the Builder."
+      )
+      raise StructIsNotInlineError(msg)
+
+  def Slot(self, slotnum):
+    """Slot sets the vtable key `voffset` to the current location in the
+
+    buffer.
+    """
+    self.assertNested()
+    self.current_vtable[slotnum] = self.Offset()
+
+  ## @endcond
+
+  def __Finish(self, rootTable, sizePrefix, file_identifier=None):
+    """Finish finalizes a buffer, pointing to the given `rootTable`."""
+    N.enforce_number(rootTable, N.UOffsetTFlags)
+
+    prepSize = N.UOffsetTFlags.bytewidth
+    if file_identifier is not None:
+      prepSize += N.Int32Flags.bytewidth
+    if sizePrefix:
+      prepSize += N.Int32Flags.bytewidth
+    self.Prep(self.minalign, prepSize)
+
+    if file_identifier is not None:
+      self.Prep(N.UOffsetTFlags.bytewidth, encode.FILE_IDENTIFIER_LENGTH)
+
+      # Convert bytes object file_identifier to an array of 4 8-bit integers,
+      # and use big-endian to enforce size compliance.
+      # https://docs.python.org/2/library/struct.html#format-characters
+      file_identifier = N.struct.unpack(">BBBB", file_identifier)
+      for i in range(encode.FILE_IDENTIFIER_LENGTH - 1, -1, -1):
+        # Place the bytes of the file_identifer in reverse order:
+        self.Place(file_identifier[i], N.Uint8Flags)
+
+    self.PrependUOffsetTRelative(rootTable)
+    if sizePrefix:
+      size = len(self.Bytes) - self.Head()
+      N.enforce_number(size, N.Int32Flags)
+      self.PrependInt32(size)
+    self.finished = True
+    return self.Head()
+
+  def Finish(self, rootTable, file_identifier=None):
+    """Finish finalizes a buffer, pointing to the given `rootTable`."""
+    return self.__Finish(rootTable, False, file_identifier=file_identifier)
+
+  def FinishSizePrefixed(self, rootTable, file_identifier=None):
+    """Finish finalizes a buffer, pointing to the given `rootTable`,
+
+    with the size prefixed.
+    """
+    return self.__Finish(rootTable, True, file_identifier=file_identifier)
+
+  ## @cond FLATBUFFERS_INTERNAL
+  def Prepend(self, flags, off):
+    self.Prep(flags.bytewidth, 0)
+    self.Place(off, flags)
+
+  def PrependSlot(self, flags, o, x, d):
+    if x is not None:
+      N.enforce_number(x, flags)
+    if d is not None:
+      N.enforce_number(d, flags)
+    if x != d or (self.forceDefaults and d is not None):
+      self.Prepend(flags, x)
+      self.Slot(o)
+
+  def PrependBoolSlot(self, *args):
+    self.PrependSlot(N.BoolFlags, *args)
+
+  def PrependByteSlot(self, *args):
+    self.PrependSlot(N.Uint8Flags, *args)
+
+  def PrependUint8Slot(self, *args):
+    self.PrependSlot(N.Uint8Flags, *args)
+
+  def PrependUint16Slot(self, *args):
+    self.PrependSlot(N.Uint16Flags, *args)
+
+  def PrependUint32Slot(self, *args):
+    self.PrependSlot(N.Uint32Flags, *args)
+
+  def PrependUint64Slot(self, *args):
+    self.PrependSlot(N.Uint64Flags, *args)
+
+  def PrependInt8Slot(self, *args):
+    self.PrependSlot(N.Int8Flags, *args)
+
+  def PrependInt16Slot(self, *args):
+    self.PrependSlot(N.Int16Flags, *args)
+
+  def PrependInt32Slot(self, *args):
+    self.PrependSlot(N.Int32Flags, *args)
+
+  def PrependInt64Slot(self, *args):
+    self.PrependSlot(N.Int64Flags, *args)
+
+  def PrependFloat32Slot(self, *args):
+    self.PrependSlot(N.Float32Flags, *args)
+
+  def PrependFloat64Slot(self, *args):
+    self.PrependSlot(N.Float64Flags, *args)
+
+  def PrependUOffsetTRelativeSlot(self, o, x, d):
+    """PrependUOffsetTRelativeSlot prepends an UOffsetT onto the object at
+
+    vtable slot `o`. If value `x` equals default `d`, then the slot will
+    be set to zero and no other data will be written.
+    """
+
+    if x != d or self.forceDefaults:
+      self.PrependUOffsetTRelative(x)
+      self.Slot(o)
+
+  def PrependStructSlot(self, v, x, d):
+    """PrependStructSlot prepends a struct onto the object at vtable slot `o`.
+
+    Structs are stored inline, so nothing additional is being added. In
+    generated code, `d` is always 0.
+    """
+
+    N.enforce_number(d, N.UOffsetTFlags)
+    if x != d:
+      self.assertStructIsInline(x)
+      self.Slot(v)
+
+  ## @endcond
+
+  def PrependBool(self, x):
+    """Prepend a `bool` to the Builder buffer.
+
+    Note: aligns and checks for space.
+    """
+    self.Prepend(N.BoolFlags, x)
+
+  def PrependByte(self, x):
+    """Prepend a `byte` to the Builder buffer.
+
+    Note: aligns and checks for space.
+    """
+    self.Prepend(N.Uint8Flags, x)
+
+  def PrependUint8(self, x):
+    """Prepend an `uint8` to the Builder buffer.
+
+    Note: aligns and checks for space.
+    """
+    self.Prepend(N.Uint8Flags, x)
+
+  def PrependUint16(self, x):
+    """Prepend an `uint16` to the Builder buffer.
+
+    Note: aligns and checks for space.
+    """
+    self.Prepend(N.Uint16Flags, x)
+
+  def PrependUint32(self, x):
+    """Prepend an `uint32` to the Builder buffer.
+
+    Note: aligns and checks for space.
+    """
+    self.Prepend(N.Uint32Flags, x)
+
+  def PrependUint64(self, x):
+    """Prepend an `uint64` to the Builder buffer.
+
+    Note: aligns and checks for space.
+    """
+    self.Prepend(N.Uint64Flags, x)
+
+  def PrependInt8(self, x):
+    """Prepend an `int8` to the Builder buffer.
+
+    Note: aligns and checks for space.
+    """
+    self.Prepend(N.Int8Flags, x)
+
+  def PrependInt16(self, x):
+    """Prepend an `int16` to the Builder buffer.
+
+    Note: aligns and checks for space.
+    """
+    self.Prepend(N.Int16Flags, x)
+
+  def PrependInt32(self, x):
+    """Prepend an `int32` to the Builder buffer.
+
+    Note: aligns and checks for space.
+    """
+    self.Prepend(N.Int32Flags, x)
+
+  def PrependInt64(self, x):
+    """Prepend an `int64` to the Builder buffer.
+
+    Note: aligns and checks for space.
+    """
+    self.Prepend(N.Int64Flags, x)
+
+  def PrependFloat32(self, x):
+    """Prepend a `float32` to the Builder buffer.
+
+    Note: aligns and checks for space.
+    """
+    self.Prepend(N.Float32Flags, x)
+
+  def PrependFloat64(self, x):
+    """Prepend a `float64` to the Builder buffer.
+
+    Note: aligns and checks for space.
+    """
+    self.Prepend(N.Float64Flags, x)
+
+  def ForceDefaults(self, forceDefaults):
+    """In order to save space, fields that are set to their default value
+
+    don't get serialized into the buffer. Forcing defaults provides a
+    way to manually disable this optimization. When set to `True`, will
+    always serialize default values.
+    """
+    self.forceDefaults = forceDefaults
+
+  ##############################################################
+
+  ## @cond FLATBUFFERS_INTERNAL
+  def PrependVOffsetT(self, x):
+    self.Prepend(N.VOffsetTFlags, x)
+
+  def Place(self, x, flags):
+    """Place prepends a value specified by `flags` to the Builder,
+
+    without checking for available space.
+    """
+
+    N.enforce_number(x, flags)
+    self.head = self.head - flags.bytewidth
+    encode.Write(flags.packer_type, self.Bytes, self.Head(), x)
+
+  def PlaceVOffsetT(self, x):
+    """PlaceVOffsetT prepends a VOffsetT to the Builder, without checking
+
+    for space.
+    """
+    N.enforce_number(x, N.VOffsetTFlags)
+    self.head = self.head - N.VOffsetTFlags.bytewidth
+    encode.Write(packer.voffset, self.Bytes, self.Head(), x)
+
+  def PlaceSOffsetT(self, x):
+    """PlaceSOffsetT prepends a SOffsetT to the Builder, without checking
+
+    for space.
+    """
+    N.enforce_number(x, N.SOffsetTFlags)
+    self.head = self.head - N.SOffsetTFlags.bytewidth
+    encode.Write(packer.soffset, self.Bytes, self.Head(), x)
+
+  def PlaceUOffsetT(self, x):
+    """PlaceUOffsetT prepends a UOffsetT to the Builder, without checking
+
+    for space.
+    """
+    N.enforce_number(x, N.UOffsetTFlags)
+    self.head = self.head - N.UOffsetTFlags.bytewidth
+    encode.Write(packer.uoffset, self.Bytes, self.Head(), x)
+
+  ## @endcond
+
+
+## @cond FLATBUFFERS_INTERNAL
+def vtableEqual(a, objectStart, b):
+  """vtableEqual compares an unwritten vtable to a written vtable."""
+
+  N.enforce_number(objectStart, N.UOffsetTFlags)
+
+  if len(a) * N.VOffsetTFlags.bytewidth != len(b):
+    return False
+
+  for i, elem in enumerate(a):
+    x = encode.Get(packer.voffset, b, i * N.VOffsetTFlags.bytewidth)
+
+    # Skip vtable entries that indicate a default value.
+    if x == 0 and elem == 0:
+      pass
+    else:
+      y = objectStart - elem
+      if x != y:
+        return False
+  return True
+
+
+## @endcond
+## @}

backend_service/venv/lib/python3.13/site-packages/flatbuffers/compat.py

@@ -0,0 +1,91 @@
+# Copyright 2016 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""A tiny version of `six` to help with backwards compability.
+
+Also includes compatibility helpers for numpy.
+"""
+
+import sys
+
+PY2 = sys.version_info[0] == 2
+PY26 = sys.version_info[0:2] == (2, 6)
+PY27 = sys.version_info[0:2] == (2, 7)
+PY275 = sys.version_info[0:3] >= (2, 7, 5)
+PY3 = sys.version_info[0] == 3
+PY34 = sys.version_info[0:2] >= (3, 4)
+
+if PY3:
+  import importlib.machinery
+
+  string_types = (str,)
+  binary_types = (bytes, bytearray)
+  range_func = range
+  memoryview_type = memoryview
+  struct_bool_decl = "?"
+else:
+  import imp
+
+  string_types = (unicode,)
+  if PY26 or PY27:
+    binary_types = (str, bytearray)
+  else:
+    binary_types = (str,)
+  range_func = xrange
+  if PY26 or (PY27 and not PY275):
+    memoryview_type = buffer
+    struct_bool_decl = "<b"
+  else:
+    memoryview_type = memoryview
+    struct_bool_decl = "?"
+
+# Helper functions to facilitate making numpy optional instead of required
+
+
+def import_numpy():
+  """Returns the numpy module if it exists on the system,
+
+  otherwise returns None.
+  """
+  if PY3:
+    numpy_exists = importlib.machinery.PathFinder.find_spec("numpy") is not None
+  else:
+    try:
+      imp.find_module("numpy")
+      numpy_exists = True
+    except ImportError:
+      numpy_exists = False
+
+  if numpy_exists:
+    # We do this outside of try/except block in case numpy exists
+    # but is not installed correctly. We do not want to catch an
+    # incorrect installation which would manifest as an
+    # ImportError.
+    import numpy as np
+  else:
+    np = None
+
+  return np
+
+
+class NumpyRequiredForThisFeature(RuntimeError):
+  """Error raised when user tries to use a feature that
+
+  requires numpy without having numpy installed.
+  """
+
+  pass
+
+
+# NOTE: Future Jython support may require code here (look at `six`).

backend_service/venv/lib/python3.13/site-packages/flatbuffers/encode.py

@@ -0,0 +1,45 @@
+# Copyright 2014 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from . import number_types as N
+from . import packer
+from .compat import memoryview_type
+from .compat import NumpyRequiredForThisFeature, import_numpy
+
+np = import_numpy()
+
+FILE_IDENTIFIER_LENGTH = 4
+
+
+def Get(packer_type, buf, head):
+  """Get decodes a value at buf[head] using `packer_type`."""
+  return packer_type.unpack_from(memoryview_type(buf), head)[0]
+
+
+def GetVectorAsNumpy(numpy_type, buf, count, offset):
+  """GetVecAsNumpy decodes values starting at buf[head] as
+
+  `numpy_type`, where `numpy_type` is a numpy dtype.
+  """
+  if np is not None:
+    # TODO: could set .flags.writeable = False to make users jump through
+    #       hoops before modifying...
+    return np.frombuffer(buf, dtype=numpy_type, count=count, offset=offset)
+  else:
+    raise NumpyRequiredForThisFeature('Numpy was not found.')
+
+
+def Write(packer_type, buf, head, n):
+  """Write encodes `n` at buf[head] using `packer_type`."""
+  packer_type.pack_into(buf, head, n)

backend_service/venv/lib/python3.13/site-packages/flatbuffers/number_types.py

@@ -0,0 +1,182 @@
+# Copyright 2014 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import collections
+import struct
+
+from . import packer
+from .compat import NumpyRequiredForThisFeature, import_numpy
+
+np = import_numpy()
+
+# For reference, see:
+# https://docs.python.org/2/library/ctypes.html#ctypes-fundamental-data-types-2
+
+# These classes could be collections.namedtuple instances, but those are new
+# in 2.6 and we want to work towards 2.5 compatability.
+
+
+class BoolFlags(object):
+  bytewidth = 1
+  min_val = False
+  max_val = True
+  py_type = bool
+  name = "bool"
+  packer_type = packer.boolean
+
+
+class Uint8Flags(object):
+  bytewidth = 1
+  min_val = 0
+  max_val = (2**8) - 1
+  py_type = int
+  name = "uint8"
+  packer_type = packer.uint8
+
+
+class Uint16Flags(object):
+  bytewidth = 2
+  min_val = 0
+  max_val = (2**16) - 1
+  py_type = int
+  name = "uint16"
+  packer_type = packer.uint16
+
+
+class Uint32Flags(object):
+  bytewidth = 4
+  min_val = 0
+  max_val = (2**32) - 1
+  py_type = int
+  name = "uint32"
+  packer_type = packer.uint32
+
+
+class Uint64Flags(object):
+  bytewidth = 8
+  min_val = 0
+  max_val = (2**64) - 1
+  py_type = int
+  name = "uint64"
+  packer_type = packer.uint64
+
+
+class Int8Flags(object):
+  bytewidth = 1
+  min_val = -(2**7)
+  max_val = (2**7) - 1
+  py_type = int
+  name = "int8"
+  packer_type = packer.int8
+
+
+class Int16Flags(object):
+  bytewidth = 2
+  min_val = -(2**15)
+  max_val = (2**15) - 1
+  py_type = int
+  name = "int16"
+  packer_type = packer.int16
+
+
+class Int32Flags(object):
+  bytewidth = 4
+  min_val = -(2**31)
+  max_val = (2**31) - 1
+  py_type = int
+  name = "int32"
+  packer_type = packer.int32
+
+
+class Int64Flags(object):
+  bytewidth = 8
+  min_val = -(2**63)
+  max_val = (2**63) - 1
+  py_type = int
+  name = "int64"
+  packer_type = packer.int64
+
+
+class Float32Flags(object):
+  bytewidth = 4
+  min_val = None
+  max_val = None
+  py_type = float
+  name = "float32"
+  packer_type = packer.float32
+
+
+class Float64Flags(object):
+  bytewidth = 8
+  min_val = None
+  max_val = None
+  py_type = float
+  name = "float64"
+  packer_type = packer.float64
+
+
+class SOffsetTFlags(Int32Flags):
+  pass
+
+
+class UOffsetTFlags(Uint32Flags):
+  pass
+
+
+class VOffsetTFlags(Uint16Flags):
+  pass
+
+
+def valid_number(n, flags):
+  if flags.min_val is None and flags.max_val is None:
+    return True
+  return flags.min_val <= n <= flags.max_val
+
+
+def enforce_number(n, flags):
+  if flags.min_val is None and flags.max_val is None:
+    return
+  if not flags.min_val <= n <= flags.max_val:
+    raise TypeError("bad number %s for type %s" % (str(n), flags.name))
+
+
+def float32_to_uint32(n):
+  packed = struct.pack("<1f", n)
+  (converted,) = struct.unpack("<1L", packed)
+  return converted
+
+
+def uint32_to_float32(n):
+  packed = struct.pack("<1L", n)
+  (unpacked,) = struct.unpack("<1f", packed)
+  return unpacked
+
+
+def float64_to_uint64(n):
+  packed = struct.pack("<1d", n)
+  (converted,) = struct.unpack("<1Q", packed)
+  return converted
+
+
+def uint64_to_float64(n):
+  packed = struct.pack("<1Q", n)
+  (unpacked,) = struct.unpack("<1d", packed)
+  return unpacked
+
+
+def to_numpy_type(number_type):
+  if np is not None:
+    return np.dtype(number_type.name).newbyteorder("<")
+  else:
+    raise NumpyRequiredForThisFeature("Numpy was not found.")

backend_service/venv/lib/python3.13/site-packages/flatbuffers/packer.py

@@ -0,0 +1,41 @@
+# Copyright 2016 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Provide pre-compiled struct packers for encoding and decoding.
+
+See: https://docs.python.org/2/library/struct.html#format-characters
+"""
+
+import struct
+from . import compat
+
+
+boolean = struct.Struct(compat.struct_bool_decl)
+
+uint8 = struct.Struct("<B")
+uint16 = struct.Struct("<H")
+uint32 = struct.Struct("<I")
+uint64 = struct.Struct("<Q")
+
+int8 = struct.Struct("<b")
+int16 = struct.Struct("<h")
+int32 = struct.Struct("<i")
+int64 = struct.Struct("<q")
+
+float32 = struct.Struct("<f")
+float64 = struct.Struct("<d")
+
+uoffset = uint32
+soffset = int32
+voffset = uint16

backend_service/venv/lib/python3.13/site-packages/flatbuffers/table.py

@@ -0,0 +1,148 @@
+# Copyright 2014 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from . import encode
+from . import number_types as N
+
+
+class Table(object):
+  """Table wraps a byte slice and provides read access to its data.
+
+  The variable `Pos` indicates the root of the FlatBuffers object therein.
+  """
+
+  __slots__ = ("Bytes", "Pos")
+
+  def __init__(self, buf, pos):
+    N.enforce_number(pos, N.UOffsetTFlags)
+
+    self.Bytes = buf
+    self.Pos = pos
+
+  def Offset(self, vtableOffset):
+    """Offset provides access into the Table's vtable.
+
+    Deprecated fields are ignored by checking the vtable's length.
+    """
+
+    vtable = self.Pos - self.Get(N.SOffsetTFlags, self.Pos)
+    vtableEnd = self.Get(N.VOffsetTFlags, vtable)
+    if vtableOffset < vtableEnd:
+      return self.Get(N.VOffsetTFlags, vtable + vtableOffset)
+    return 0
+
+  def Indirect(self, off):
+    """Indirect retrieves the relative offset stored at `offset`."""
+    N.enforce_number(off, N.UOffsetTFlags)
+    return off + encode.Get(N.UOffsetTFlags.packer_type, self.Bytes, off)
+
+  def String(self, off):
+    """String gets a string from data stored inside the flatbuffer."""
+    N.enforce_number(off, N.UOffsetTFlags)
+    off += encode.Get(N.UOffsetTFlags.packer_type, self.Bytes, off)
+    start = off + N.UOffsetTFlags.bytewidth
+    length = encode.Get(N.UOffsetTFlags.packer_type, self.Bytes, off)
+    return bytes(self.Bytes[start : start + length])
+
+  def VectorLen(self, off):
+    """VectorLen retrieves the length of the vector whose offset is stored
+
+    at "off" in this object.
+    """
+    N.enforce_number(off, N.UOffsetTFlags)
+
+    off += self.Pos
+    off += encode.Get(N.UOffsetTFlags.packer_type, self.Bytes, off)
+    ret = encode.Get(N.UOffsetTFlags.packer_type, self.Bytes, off)
+    return ret
+
+  def Vector(self, off):
+    """Vector retrieves the start of data of the vector whose offset is
+
+    stored at "off" in this object.
+    """
+    N.enforce_number(off, N.UOffsetTFlags)
+
+    off += self.Pos
+    x = off + self.Get(N.UOffsetTFlags, off)
+    # data starts after metadata containing the vector length
+    x += N.UOffsetTFlags.bytewidth
+    return x
+
+  def Union(self, t2, off):
+    """Union initializes any Table-derived type to point to the union at
+
+    the given offset.
+    """
+    assert type(t2) is Table
+    N.enforce_number(off, N.UOffsetTFlags)
+
+    off += self.Pos
+    t2.Pos = off + self.Get(N.UOffsetTFlags, off)
+    t2.Bytes = self.Bytes
+
+  def Get(self, flags, off):
+    """Get retrieves a value of the type specified by `flags`  at the
+
+    given offset.
+    """
+    N.enforce_number(off, N.UOffsetTFlags)
+    return flags.py_type(encode.Get(flags.packer_type, self.Bytes, off))
+
+  def GetSlot(self, slot, d, validator_flags):
+    N.enforce_number(slot, N.VOffsetTFlags)
+    if validator_flags is not None:
+      N.enforce_number(d, validator_flags)
+    off = self.Offset(slot)
+    if off == 0:
+      return d
+    return self.Get(validator_flags, self.Pos + off)
+
+  def GetVectorAsNumpy(self, flags, off):
+    """GetVectorAsNumpy returns the vector that starts at `Vector(off)`
+
+    as a numpy array with the type specified by `flags`. The array is
+    a `view` into Bytes, so modifying the returned array will
+    modify Bytes in place.
+    """
+    offset = self.Vector(off)
+    length = self.VectorLen(off)  # TODO: length accounts for bytewidth, right?
+    numpy_dtype = N.to_numpy_type(flags)
+    return encode.GetVectorAsNumpy(numpy_dtype, self.Bytes, length, offset)
+
+  def GetArrayAsNumpy(self, flags, off, length):
+    """GetArrayAsNumpy returns the array with fixed width that starts at `Vector(offset)`
+
+    with length `length` as a numpy array with the type specified by `flags`.
+    The
+    array is a `view` into Bytes so modifying the returned will modify Bytes in
+    place.
+    """
+    numpy_dtype = N.to_numpy_type(flags)
+    return encode.GetVectorAsNumpy(numpy_dtype, self.Bytes, length, off)
+
+  def GetVOffsetTSlot(self, slot, d):
+    """GetVOffsetTSlot retrieves the VOffsetT that the given vtable location
+
+    points to. If the vtable value is zero, the default value `d`
+    will be returned.
+    """
+
+    N.enforce_number(slot, N.VOffsetTFlags)
+    N.enforce_number(d, N.VOffsetTFlags)
+
+    off = self.Offset(slot)
+    if off == 0:
+      return d
+    return off

backend_service/venv/lib/python3.13/site-packages/flatbuffers/util.py

@@ -0,0 +1,47 @@
+# Copyright 2017 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from . import encode
+from . import number_types
+from . import packer
+
+
+def GetSizePrefix(buf, offset):
+  """Extract the size prefix from a buffer."""
+  return encode.Get(packer.int32, buf, offset)
+
+
+def GetBufferIdentifier(buf, offset, size_prefixed=False):
+  """Extract the file_identifier from a buffer"""
+  if size_prefixed:
+    # increase offset by size of UOffsetTFlags
+    offset += number_types.UOffsetTFlags.bytewidth
+  # increase offset by size of root table pointer
+  offset += number_types.UOffsetTFlags.bytewidth
+  # end of FILE_IDENTIFIER
+  end = offset + encode.FILE_IDENTIFIER_LENGTH
+  return buf[offset:end]
+
+
+def BufferHasIdentifier(buf, offset, file_identifier, size_prefixed=False):
+  got = GetBufferIdentifier(buf, offset, size_prefixed=size_prefixed)
+  return got == file_identifier
+
+
+def RemoveSizePrefix(buf, offset):
+  """Create a slice of a size-prefixed buffer that has
+
+  its position advanced just past the size prefix.
+  """
+  return buf, offset + number_types.Int32Flags.bytewidth