@tanstack/db/dist/esm/query/compiler/joins.js

A reactive client store for building super fast apps on sync

import { map, join, consolidate, filter } from "@tanstack/db-ivm";
import { UnsupportedJoinTypeError, UnsupportedJoinSourceTypeError, CollectionInputNotFoundError, InvalidJoinConditionSameTableError, InvalidJoinConditionTableMismatchError, InvalidJoinConditionWrongTablesError } from "../../errors.js";
import { compileExpression } from "./evaluators.js";
import { compileQuery } from "./index.js";
function processJoins(pipeline, joinClauses, tables, mainTableAlias, allInputs, cache, queryMapping) {
  let resultPipeline = pipeline;
  for (const joinClause of joinClauses) {
    resultPipeline = processJoin(
      resultPipeline,
      joinClause,
      tables,
      mainTableAlias,
      allInputs,
      cache,
      queryMapping
    );
  }
  return resultPipeline;
}
function processJoin(pipeline, joinClause, tables, mainTableAlias, allInputs, cache, queryMapping) {
  const { alias: joinedTableAlias, input: joinedInput } = processJoinSource(
    joinClause.from,
    allInputs,
    cache,
    queryMapping
  );
  tables[joinedTableAlias] = joinedInput;
  const joinType = joinClause.type === `cross` ? `inner` : joinClause.type === `outer` ? `full` : joinClause.type;
  const { mainExpr, joinedExpr } = analyzeJoinExpressions(
    joinClause.left,
    joinClause.right,
    mainTableAlias,
    joinedTableAlias
  );
  const compiledMainExpr = compileExpression(mainExpr);
  const compiledJoinedExpr = compileExpression(joinedExpr);
  const mainPipeline = pipeline.pipe(
    map(([currentKey, namespacedRow]) => {
      const mainKey = compiledMainExpr(namespacedRow);
      return [mainKey, [currentKey, namespacedRow]];
    })
  );
  const joinedPipeline = joinedInput.pipe(
    map(([currentKey, row]) => {
      const namespacedRow = { [joinedTableAlias]: row };
      const joinedKey = compiledJoinedExpr(namespacedRow);
      return [joinedKey, [currentKey, namespacedRow]];
    })
  );
  if (![`inner`, `left`, `right`, `full`].includes(joinType)) {
    throw new UnsupportedJoinTypeError(joinClause.type);
  }
  return mainPipeline.pipe(
    join(joinedPipeline, joinType),
    consolidate(),
    processJoinResults(joinClause.type)
  );
}
function analyzeJoinExpressions(left, right, mainTableAlias, joinedTableAlias) {
  const leftTableAlias = getTableAliasFromExpression(left);
  const rightTableAlias = getTableAliasFromExpression(right);
  if (leftTableAlias === mainTableAlias && rightTableAlias === joinedTableAlias) {
    return { mainExpr: left, joinedExpr: right };
  }
  if (leftTableAlias === joinedTableAlias && rightTableAlias === mainTableAlias) {
    return { mainExpr: right, joinedExpr: left };
  }
  if (leftTableAlias === rightTableAlias) {
    throw new InvalidJoinConditionSameTableError(leftTableAlias || `unknown`);
  }
  if (!leftTableAlias || !rightTableAlias) {
    throw new InvalidJoinConditionTableMismatchError(
      mainTableAlias,
      joinedTableAlias
    );
  }
  throw new InvalidJoinConditionWrongTablesError(
    leftTableAlias,
    rightTableAlias,
    mainTableAlias,
    joinedTableAlias
  );
}
function getTableAliasFromExpression(expr) {
  switch (expr.type) {
    case `ref`:
      return expr.path[0] || null;
    case `func`: {
      const tableAliases = /* @__PURE__ */ new Set();
      for (const arg of expr.args) {
        const alias = getTableAliasFromExpression(arg);
        if (alias) {
          tableAliases.add(alias);
        }
      }
      return tableAliases.size === 1 ? Array.from(tableAliases)[0] : null;
    }
    default:
      return null;
  }
}
function processJoinSource(from, allInputs, cache, queryMapping) {
  switch (from.type) {
    case `collectionRef`: {
      const input = allInputs[from.collection.id];
      if (!input) {
        throw new CollectionInputNotFoundError(from.collection.id);
      }
      return { alias: from.alias, input };
    }
    case `queryRef`: {
      const originalQuery = queryMapping.get(from.query) || from.query;
      const subQueryResult = compileQuery(
        originalQuery,
        allInputs,
        cache,
        queryMapping
      );
      const subQueryInput = subQueryResult.pipeline;
      const extractedInput = subQueryInput.pipe(
        map((data) => {
          const [key, [value, _orderByIndex]] = data;
          return [key, value];
        })
      );
      return { alias: from.alias, input: extractedInput };
    }
    default:
      throw new UnsupportedJoinSourceTypeError(from.type);
  }
}
function processJoinResults(joinType) {
  return function(pipeline) {
    return pipeline.pipe(
      // Process the join result and handle nulls
      filter((result) => {
        const [_key, [main, joined]] = result;
        const mainNamespacedRow = main == null ? void 0 : main[1];
        const joinedNamespacedRow = joined == null ? void 0 : joined[1];
        if (joinType === `inner`) {
          return !!(mainNamespacedRow && joinedNamespacedRow);
        }
        if (joinType === `left`) {
          return !!mainNamespacedRow;
        }
        if (joinType === `right`) {
          return !!joinedNamespacedRow;
        }
        return true;
      }),
      map((result) => {
        const [_key, [main, joined]] = result;
        const mainKey = main == null ? void 0 : main[0];
        const mainNamespacedRow = main == null ? void 0 : main[1];
        const joinedKey = joined == null ? void 0 : joined[0];
        const joinedNamespacedRow = joined == null ? void 0 : joined[1];
        const mergedNamespacedRow = {};
        if (mainNamespacedRow) {
          Object.assign(mergedNamespacedRow, mainNamespacedRow);
        }
        if (joinedNamespacedRow) {
          Object.assign(mergedNamespacedRow, joinedNamespacedRow);
        }
        const resultKey = `[${mainKey},${joinedKey}]`;
        return [resultKey, mergedNamespacedRow];
      })
    );
  };
}
export {
  processJoins
};
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