prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  Internal server error when importing CSVs with long names
  Follow the same steps as reported in #2634 and observer the error from the screenshot below: 
  
  API: `http://localhost/api/db/v0/tables/12/records/?limit=500&offset=0`
  
  <img width="1512" alt="Screenshot 2023-03-20 at 5 29 52 AM" src="https://user-images.githubusercontent.com/11032856/226218521-75355de8-eee0-4b5e-9a9c-47aa3ff67da2.png">
  
  
  --- END ISSUE ---
  
  Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
  --- BEGIN FILES ---
  Path: `db/identifiers.py`
  Content:
  ```
  1 import hashlib
  2 
  3 
  4 def truncate_if_necessary(identifier):
  5     """
  6     Takes an identifier and returns it, truncating it, if it is too long. The truncated version
  7     will end with a hash of the passed identifier, therefore column name collision should be very
  8     rare.
  9 
  10     Iteratively removes characters from the end of the identifier, until the resulting string, with
  11     the suffix hash of the identifier appended, is short enough that it doesn't need to be truncated
  12     anymore. Whitespace is trimmed from the truncated identifier before appending the suffix.
  13     """
  14     assert type(identifier) is str
  15     if not is_identifier_too_long(identifier):
  16         return identifier
  17     right_side = "-" + _get_truncation_hash(identifier)
  18     identifier_length = len(identifier)
  19     assert len(right_side) < identifier_length  # Sanity check
  20     range_of_num_of_chars_to_remove = range(1, identifier_length)
  21     for num_of_chars_to_remove in range_of_num_of_chars_to_remove:
  22         left_side = identifier[:num_of_chars_to_remove * -1]
  23         left_side = left_side.rstrip()
  24         truncated_identifier = left_side + right_side
  25         if not is_identifier_too_long(truncated_identifier):
  26             return truncated_identifier
  27     raise Exception(
  28         "Acceptable truncation not found; should never happen."
  29     )
  30 
  31 
  32 def is_identifier_too_long(identifier):
  33     postgres_identifier_size_limit = 63
  34     size = _get_size_of_identifier_in_bytes(identifier)
  35     return size > postgres_identifier_size_limit
  36 
  37 
  38 def _get_truncation_hash(identifier):
  39     """
  40     Produces an 8-character string hash of the passed identifier.
  41 
  42     Using hash function blake2s, because it seems fairly recommended and it seems to be better
  43     suited for shorter digests than blake2b. We want short digests to not take up too much of the
  44     truncated identifier in whose construction this will be used.
  45     """
  46     h = hashlib.blake2s(digest_size=4)
  47     bytes = _get_identifier_in_bytes(identifier)
  48     h.update(bytes)
  49     return h.hexdigest()
  50 
  51 
  52 def _get_size_of_identifier_in_bytes(s):
  53     bytes = _get_identifier_in_bytes(s)
  54     return len(bytes)
  55 
  56 
  57 def _get_identifier_in_bytes(s):
  58     """
  59     Afaict, following Postgres doc [0] says that UTF-8 supports all languages; therefore, different
  60     server locale configurations should not break this.
  61 
  62     [0] https://www.postgresql.org/docs/13/multibyte.html
  63     """
  64     return s.encode('utf-8')
  65
  ```
  --- END FILES ---
  
  Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.
  
  Here is an example:
  
  ```diff
  diff --git a/examples/server_async.py b/examples/server_async.py
  --- a/examples/server_async.py
  +++ b/examples/server_async.py
  @@ -313,4 +313,4 @@
   
   
   if __name__ == "__main__":
  -    asyncio.run(run_async_server("."), debug=True)
  +    asyncio.run(run_async_server(), debug=True)
  diff --git a/examples/server_sync.py b/examples/server_sync.py
  --- a/examples/server_sync.py
  +++ b/examples/server_sync.py
  @@ -313,5 +313,5 @@
   
   
   if __name__ == "__main__":
  -    server = run_sync_server(".")
  +    server = run_sync_server()
       server.shutdown()
  
  ```
  
golden_diff: diff --git a/db/identifiers.py b/db/identifiers.py
  --- a/db/identifiers.py
  +++ b/db/identifiers.py
  @@ -1,6 +1,9 @@
   import hashlib
   
   
  +POSTGRES_IDENTIFIER_SIZE_LIMIT = 63
  +
  +
   def truncate_if_necessary(identifier):
       """
       Takes an identifier and returns it, truncating it, if it is too long. The truncated version
  @@ -30,9 +33,13 @@
   
   
   def is_identifier_too_long(identifier):
  -    postgres_identifier_size_limit = 63
  +    # TODO we should support POSTGRES_IDENTIFIER_SIZE_LIMIT here;
  +    # Our current limit due to an unknown bug that manifests at least
  +    # when importing CSVs seems to be 57 bytes. Here we're setting it even
  +    # lower just in case.
  +    our_temporary_identifier_size_limit = 48
       size = _get_size_of_identifier_in_bytes(identifier)
  -    return size > postgres_identifier_size_limit
  +    return size > our_temporary_identifier_size_limit
   
   
   def _get_truncation_hash(identifier):
  
verification_info: {"golden_diff": "diff --git a/db/identifiers.py b/db/identifiers.py\n--- a/db/identifiers.py\n+++ b/db/identifiers.py\n@@ -1,6 +1,9 @@\n import hashlib\n \n \n+POSTGRES_IDENTIFIER_SIZE_LIMIT = 63\n+\n+\n def truncate_if_necessary(identifier):\n     \"\"\"\n     Takes an identifier and returns it, truncating it, if it is too long. The truncated version\n@@ -30,9 +33,13 @@\n \n \n def is_identifier_too_long(identifier):\n-    postgres_identifier_size_limit = 63\n+    # TODO we should support POSTGRES_IDENTIFIER_SIZE_LIMIT here;\n+    # Our current limit due to an unknown bug that manifests at least\n+    # when importing CSVs seems to be 57 bytes. Here we're setting it even\n+    # lower just in case.\n+    our_temporary_identifier_size_limit = 48\n     size = _get_size_of_identifier_in_bytes(identifier)\n-    return size > postgres_identifier_size_limit\n+    return size > our_temporary_identifier_size_limit\n \n \n def _get_truncation_hash(identifier):\n", "issue": "Internal server error when importing CSVs with long names\nFollow the same steps as reported in #2634 and observer the error from the screenshot below: \r\n\r\nAPI: `http://localhost/api/db/v0/tables/12/records/?limit=500&offset=0`\r\n\r\n<img width=\"1512\" alt=\"Screenshot 2023-03-20 at 5 29 52 AM\" src=\"https://user-images.githubusercontent.com/11032856/226218521-75355de8-eee0-4b5e-9a9c-47aa3ff67da2.png\">\r\n\n", "before_files": [{"content": "import hashlib\n\n\ndef truncate_if_necessary(identifier):\n    \"\"\"\n    Takes an identifier and returns it, truncating it, if it is too long. The truncated version\n    will end with a hash of the passed identifier, therefore column name collision should be very\n    rare.\n\n    Iteratively removes characters from the end of the identifier, until the resulting string, with\n    the suffix hash of the identifier appended, is short enough that it doesn't need to be truncated\n    anymore. Whitespace is trimmed from the truncated identifier before appending the suffix.\n    \"\"\"\n    assert type(identifier) is str\n    if not is_identifier_too_long(identifier):\n        return identifier\n    right_side = \"-\" + _get_truncation_hash(identifier)\n    identifier_length = len(identifier)\n    assert len(right_side) < identifier_length  # Sanity check\n    range_of_num_of_chars_to_remove = range(1, identifier_length)\n    for num_of_chars_to_remove in range_of_num_of_chars_to_remove:\n        left_side = identifier[:num_of_chars_to_remove * -1]\n        left_side = left_side.rstrip()\n        truncated_identifier = left_side + right_side\n        if not is_identifier_too_long(truncated_identifier):\n            return truncated_identifier\n    raise Exception(\n        \"Acceptable truncation not found; should never happen.\"\n    )\n\n\ndef is_identifier_too_long(identifier):\n    postgres_identifier_size_limit = 63\n    size = _get_size_of_identifier_in_bytes(identifier)\n    return size > postgres_identifier_size_limit\n\n\ndef _get_truncation_hash(identifier):\n    \"\"\"\n    Produces an 8-character string hash of the passed identifier.\n\n    Using hash function blake2s, because it seems fairly recommended and it seems to be better\n    suited for shorter digests than blake2b. We want short digests to not take up too much of the\n    truncated identifier in whose construction this will be used.\n    \"\"\"\n    h = hashlib.blake2s(digest_size=4)\n    bytes = _get_identifier_in_bytes(identifier)\n    h.update(bytes)\n    return h.hexdigest()\n\n\ndef _get_size_of_identifier_in_bytes(s):\n    bytes = _get_identifier_in_bytes(s)\n    return len(bytes)\n\n\ndef _get_identifier_in_bytes(s):\n    \"\"\"\n    Afaict, following Postgres doc [0] says that UTF-8 supports all languages; therefore, different\n    server locale configurations should not break this.\n\n    [0] https://www.postgresql.org/docs/13/multibyte.html\n    \"\"\"\n    return s.encode('utf-8')\n", "path": "db/identifiers.py"}], "after_files": [{"content": "import hashlib\n\n\nPOSTGRES_IDENTIFIER_SIZE_LIMIT = 63\n\n\ndef truncate_if_necessary(identifier):\n    \"\"\"\n    Takes an identifier and returns it, truncating it, if it is too long. The truncated version\n    will end with a hash of the passed identifier, therefore column name collision should be very\n    rare.\n\n    Iteratively removes characters from the end of the identifier, until the resulting string, with\n    the suffix hash of the identifier appended, is short enough that it doesn't need to be truncated\n    anymore. Whitespace is trimmed from the truncated identifier before appending the suffix.\n    \"\"\"\n    assert type(identifier) is str\n    if not is_identifier_too_long(identifier):\n        return identifier\n    right_side = \"-\" + _get_truncation_hash(identifier)\n    identifier_length = len(identifier)\n    assert len(right_side) < identifier_length  # Sanity check\n    range_of_num_of_chars_to_remove = range(1, identifier_length)\n    for num_of_chars_to_remove in range_of_num_of_chars_to_remove:\n        left_side = identifier[:num_of_chars_to_remove * -1]\n        left_side = left_side.rstrip()\n        truncated_identifier = left_side + right_side\n        if not is_identifier_too_long(truncated_identifier):\n            return truncated_identifier\n    raise Exception(\n        \"Acceptable truncation not found; should never happen.\"\n    )\n\n\ndef is_identifier_too_long(identifier):\n    # TODO we should support POSTGRES_IDENTIFIER_SIZE_LIMIT here;\n    # Our current limit due to an unknown bug that manifests at least\n    # when importing CSVs seems to be 57 bytes. Here we're setting it even\n    # lower just in case.\n    our_temporary_identifier_size_limit = 48\n    size = _get_size_of_identifier_in_bytes(identifier)\n    return size > our_temporary_identifier_size_limit\n\n\ndef _get_truncation_hash(identifier):\n    \"\"\"\n    Produces an 8-character string hash of the passed identifier.\n\n    Using hash function blake2s, because it seems fairly recommended and it seems to be better\n    suited for shorter digests than blake2b. We want short digests to not take up too much of the\n    truncated identifier in whose construction this will be used.\n    \"\"\"\n    h = hashlib.blake2s(digest_size=4)\n    bytes = _get_identifier_in_bytes(identifier)\n    h.update(bytes)\n    return h.hexdigest()\n\n\ndef _get_size_of_identifier_in_bytes(s):\n    bytes = _get_identifier_in_bytes(s)\n    return len(bytes)\n\n\ndef _get_identifier_in_bytes(s):\n    \"\"\"\n    Afaict, following Postgres doc [0] says that UTF-8 supports all languages; therefore, different\n    server locale configurations should not break this.\n\n    [0] https://www.postgresql.org/docs/13/multibyte.html\n    \"\"\"\n    return s.encode('utf-8')\n", "path": "db/identifiers.py"}]}