[JIT] Design document

[ryzhyk]

Document JIT architecture and API. The doc should serve two purposes:

• Explain the semantics of the bytecode supported by the JIT compiler and the architecture of the compiler. This should give the reader enough information to be able to understand the source code of the compiler.
• Explain how a frontend (e.g., the SQL compiler) and a runtime (e.g., the DBSP pipeline runner) should interact with JIT.
• Topics to cover
• String allocation and string lifetimes
• Block parameters and arguments
• How to run a JIT program
• How nested tuples can be implemented using the JIT
• How to call functions which are not built-in into the JIT (if there will be such functions), e.g., from the SQL runtime library
• How datatypes such as DECIMAL can be implemented
• How to pass tuples as function arguments

[Kixiron]

How to run a JIT program

I do a lot of that here, running programs from json and ingesting csv into them

[Kixiron]

Block parameters

Here's some example json

{
  "nodes": {
    "n1": {
      "Source": {
        "layout": 3
      }
    },
    "n2": {
      "Source": {
        "layout": 4
      }
    },
    "n3": {
      "IndexByColumn": {
        "input": 1,
        "input_layout": 3,
        "key_column": 0,
        "discarded_values": [
          2,
          3,
          5,
          6,
          7,
          8,
          9,
          10,
          11
        ],
        "key_layout": 5,
        "value_layout": 6
      }
    },
    "n4": {
      "IndexByColumn": {
        "input": 2,
        "input_layout": 4,
        "key_column": 1,
        "discarded_values": [
          2,
          3,
          4,
          5,
          6,
          7,
          8,
          9
        ],
        "key_layout": 5,
        "value_layout": 7
      }
    },
    "n5": {
      "JoinCore": {
        "lhs": 4,
        "rhs": 3,
        "join_fn": {
          "args": [
            {
              "id": 1,
              "layout": 5,
              "flags": "input"
            },
            {
              "id": 2,
              "layout": 7,
              "flags": "input"
            },
            {
              "id": 3,
              "layout": 6,
              "flags": "input"
            },
            {
              "id": 4,
              "layout": 8,
              "flags": "output"
            },
            {
              "id": 5,
              "layout": 1,
              "flags": "output"
            }
          ],
          "ret": "Unit",
          "entry_block": 1,
          "blocks": {
            "bb1": {
              "id": 1,
              "params": [],
              "body": [
                [
                  6,
                  {
                    "Load": {
                      "source": 2,
                      "source_layout": 7,
                      "column": 0,
                      "column_type": "Timestamp"
                    }
                  }
                ],
                [
                  7,
                  {
                    "Load": {
                      "source": 1,
                      "source_layout": 5,
                      "column": 0,
                      "column_type": "F64"
                    }
                  }
                ],
                [
                  8,
                  {
                    "Store": {
                      "target": 4,
                      "target_layout": 8,
                      "column": 0,
                      "value": {
                        "Expr": 6
                      },
                      "value_type": "Timestamp"
                    }
                  }
                ],
                [
                  9,
                  {
                    "Store": {
                      "target": 4,
                      "target_layout": 8,
                      "column": 1,
                      "value": {
                        "Expr": 7
                      },
                      "value_type": "F64"
                    }
                  }
                ],
                [
                  10,
                  {
                    "IsNull": {
                      "target": 3,
                      "target_layout": 6,
                      "column": 0
                    }
                  }
                ],
                [
                  11,
                  {
                    "SetNull": {
                      "target": 4,
                      "target_layout": 8,
                      "column": 2,
                      "is_null": {
                        "Expr": 10
                      }
                    }
                  }
                ]
              ],
              "terminator": {
                "Branch": {
                  "cond": {
                    "Expr": 10
                  },
                  "truthy": 3,
                  "true_params": [],
                  "falsy": 2,
                  "false_params": []
                }
              }
            },
            "bb2": {
              "id": 2,
              "params": [],
              "body": [
                [
                  12,
                  {
                    "Load": {
                      "source": 3,
                      "source_layout": 6,
                      "column": 0,
                      "column_type": "String"
                    }
                  }
                ],
                [
                  13,
                  {
                    "Copy": {
                      "value": 12,
                      "value_ty": "String"
                    }
                  }
                ],
                [
                  14,
                  {
                    "Store": {
                      "target": 4,
                      "target_layout": 8,
                      "column": 2,
                      "value": {
                        "Expr": 13
                      },
                      "value_type": "String"
                    }
                  }
                ]
              ],
              "terminator": {
                "Jump": {
                  "target": 3,
                  "params": []
                }
              }
            },
            "bb3": {
              "id": 3,
              "params": [],
              "body": [
                [
                  15,
                  {
                    "IsNull": {
                      "target": 3,
                      "target_layout": 6,
                      "column": 1
                    }
                  }
                ],
                [
                  16,
                  {
                    "SetNull": {
                      "target": 4,
                      "target_layout": 8,
                      "column": 3,
                      "is_null": {
                        "Expr": 15
                      }
                    }
                  }
                ]
              ],
              "terminator": {
                "Branch": {
                  "cond": {
                    "Expr": 15
                  },
                  "truthy": 5,
                  "true_params": [],
                  "falsy": 4,
                  "false_params": []
                }
              }
            },
            "bb4": {
              "id": 4,
              "params": [],
              "body": [
                [
                  17,
                  {
                    "Load": {
                      "source": 3,
                      "source_layout": 6,
                      "column": 1,
                      "column_type": "String"
                    }
                  }
                ],
                [
                  18,
                  {
                    "Copy": {
                      "value": 17,
                      "value_ty": "String"
                    }
                  }
                ],
                [
                  19,
                  {
                    "Store": {
                      "target": 4,
                      "target_layout": 8,
                      "column": 3,
                      "value": {
                        "Expr": 18
                      },
                      "value_type": "String"
                    }
                  }
                ]
              ],
              "terminator": {
                "Jump": {
                  "target": 5,
                  "params": []
                }
              }
            },
            "bb5": {
              "id": 5,
              "params": [],
              "body": [],
              "terminator": {
                "Return": {
                  "value": {
                    "Imm": "Unit"
                  }
                }
              }
            }
          }
        },
        "key_layout": 8,
        "value_layout": 1,
        "output_kind": "Set"
      }
    },
    "n6": {
      "Sink": {
        "input": 5
      }
    }
  }
}