Add get tokens endpoint

db/historydb/historydb.go

@@ -298,13 +298,75 @@ func (hdb *HistoryDB) GetToken(tokenID common.TokenID) (*TokenRead, error) {
 }
 
 // GetTokens returns a list of tokens from the DB
-func (hdb *HistoryDB) GetTokens() ([]TokenRead, error) {
-	var tokens []*TokenRead
-	err := meddler.QueryAll(
-		hdb.db, &tokens,
-		"SELECT * FROM token ORDER BY token_id;",
-	)
-	return db.SlicePtrsToSlice(tokens).([]TokenRead), err
+func (hdb *HistoryDB) GetTokens(ids []common.TokenID, symbols []string, name string, fromItem, limit *uint, order string) ([]TokenRead, *db.Pagination, error) {
+	var query string
+	var args []interface{}
+	queryStr := `SELECT * , COUNT(*) OVER() AS total_items, MIN(token.item_id) OVER() AS first_item, MAX(token.item_id) OVER() AS last_item FROM token `
+	// Apply filters
+	nextIsAnd := false
+	if len(ids) > 0 {
+		queryStr += "WHERE token_id IN (?) "
+		nextIsAnd = true
+		args = append(args, ids)
+	}
+	if len(symbols) > 0 {
+		if nextIsAnd {
+			queryStr += "AND "
+		} else {
+			queryStr += "WHERE "
+		}
+		queryStr += "symbol IN (?) "
+		args = append(args, symbols)
+		nextIsAnd = true
+	}
+	if name != "" {
+		if nextIsAnd {
+			queryStr += "AND "
+		} else {
+			queryStr += "WHERE "
+		}
+		queryStr += "name ~ ? "
+		args = append(args, name)
+		nextIsAnd = true
+	}
+	if fromItem != nil {
+		if nextIsAnd {
+			queryStr += "AND "
+		} else {
+			queryStr += "WHERE "
+		}
+		if order == OrderAsc {
+			queryStr += "item_id >= ? "
+		} else {
+			queryStr += "item_id <= ? "
+		}
+		args = append(args, fromItem)
+	}
+	// pagination
+	queryStr += "ORDER BY item_id "
+	if order == OrderAsc {
+		queryStr += "ASC "
+	} else {
+		queryStr += "DESC "
+	}
+	queryStr += fmt.Sprintf("LIMIT %d;", *limit)
+	query, argsQ, err := sqlx.In(queryStr, args...)
+	if err != nil {
+		return nil, nil, err
+	}
+	query = hdb.db.Rebind(query)
+	tokens := []*TokenRead{}
+	if err := meddler.QueryAll(hdb.db, &tokens, query, argsQ...); err != nil {
+		return nil, nil, err
+	}
+	if len(tokens) == 0 {
+		return nil, nil, sql.ErrNoRows
+	}
+	return db.SlicePtrsToSlice(tokens).([]TokenRead), &db.Pagination{
+		TotalItems: tokens[0].TotalItems,
+		FirstItem:  tokens[0].FirstItem,
+		LastItem:   tokens[0].LastItem,
+	}, nil
 }
 
 // GetTokenSymbols returns all the token symbols from the DB

db/historydb/historydb_test.go

@@ -145,8 +145,9 @@ func TestTokens(t *testing.T) {
 	tokens := test.GenTokens(nTokens, blocks)
 	err := historyDB.AddTokens(tokens)
 	assert.NoError(t, err)
-	// Fetch tokens
-	fetchedTokens, err := historyDB.GetTokens()
+	limit := uint(10)
+	// Fetch tokens6
+	fetchedTokens, _, err := historyDB.GetTokens(nil, nil, "", nil, &limit, OrderAsc)
 	assert.NoError(t, err)
 	// Compare fetched tokens vs generated tokens
 	// All the tokens should have USDUpdate setted by the DB trigger

db/historydb/views.go

@@ -81,14 +81,18 @@ type txWrite struct {
 
 // TokenRead add USD info to common.Token
 type TokenRead struct {
-	TokenID     common.TokenID    `json:"id" meddler:"token_id"`
-	EthBlockNum int64             `json:"ethereumBlockNum" meddler:"eth_block_num"` // Ethereum block number in which this token was registered
-	EthAddr     ethCommon.Address `json:"ethereumAddress" meddler:"eth_addr"`
-	Name        string            `json:"name" meddler:"name"`
-	Symbol      string            `json:"symbol" meddler:"symbol"`
-	Decimals    uint64            `json:"decimals" meddler:"decimals"`
-	USD         *float64          `json:"USD" meddler:"usd"`
-	USDUpdate   *time.Time        `json:"fiatUpdate" meddler:"usd_update,utctime"`
+	ItemID      int               `meddler:"item_id"`
+	TokenID     common.TokenID    `meddler:"token_id"`
+	EthBlockNum int64             `meddler:"eth_block_num"` // Ethereum block number in which this token was registered
+	EthAddr     ethCommon.Address `meddler:"eth_addr"`
+	Name        string            `meddler:"name"`
+	Symbol      string            `meddler:"symbol"`
+	Decimals    uint64            `meddler:"decimals"`
+	USD         *float64          `meddler:"usd"`
+	USDUpdate   *time.Time        `meddler:"usd_update,utctime"`
+	TotalItems  int               `meddler:"total_items"`
+	FirstItem   int               `meddler:"first_item"`
+	LastItem    int               `meddler:"last_item"`
 }
 
 // HistoryExit is a representation of a exit with additional information

db/migrations/0001.sql

@@ -37,7 +37,8 @@ CREATE TABLE bid (
 );
 
 CREATE TABLE token (
-    token_id INT PRIMARY KEY,
+    item_id SERIAL PRIMARY KEY,
+    token_id INT UNIQUE NOT NULL,
     eth_block_num BIGINT NOT NULL REFERENCES block (eth_block_num) ON DELETE CASCADE,
     eth_addr BYTEA UNIQUE NOT NULL,
     name VARCHAR(20) NOT NULL,