api: add /block/.../raw endpoints

Also add api/types.BlockRaw.

use strings.Builder to avoid copying a long string

api/apirouter.go

@@ -39,6 +39,7 @@ func NewAPIRouter(app *appContext, useRealIP bool) apiMux {
 			rd.Get("/height", app.currentHeight)
 			rd.Get("/hash", app.getBlockHash)
 			rd.Get("/header", app.getBlockHeader)
+			rd.Get("/raw", app.getBlockRaw)
 			rd.Get("/size", app.getBlockSize)
 			rd.Get("/subsidy", app.blockSubsidies)
 			rd.With((middleware.Compress(1))).Get("/verbose", app.getBlockVerbose)
@@ -54,6 +55,7 @@ func NewAPIRouter(app *appContext, useRealIP bool) apiMux {
 			rd.Get("/", app.getBlockSummary)
 			rd.Get("/height", app.getBlockHeight)
 			rd.Get("/header", app.getBlockHeader)
+			rd.Get("/raw", app.getBlockRaw)
 			rd.Get("/size", app.getBlockSize)
 			rd.Get("/subsidy", app.blockSubsidies)
 			rd.With((middleware.Compress(1))).Get("/verbose", app.getBlockVerbose)
@@ -69,6 +71,7 @@ func NewAPIRouter(app *appContext, useRealIP bool) apiMux {
 			rd.Get("/", app.getBlockSummary)
 			rd.Get("/header", app.getBlockHeader)
 			rd.Get("/hash", app.getBlockHash)
+			rd.Get("/raw", app.getBlockRaw)
 			rd.Get("/size", app.getBlockSize)
 			rd.Get("/subsidy", app.blockSubsidies)
 			rd.With((middleware.Compress(1))).Get("/verbose", app.getBlockVerbose)

api/apiroutes.go

@@ -9,6 +9,7 @@ import (
 	"context"
 	"database/sql"
 	"encoding/csv"
+	"encoding/hex"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -23,6 +24,7 @@ import (
 	"github.com/decred/dcrd/chaincfg"
 	"github.com/decred/dcrd/dcrjson/v2"
 	"github.com/decred/dcrd/rpcclient/v2"
+	"github.com/decred/dcrd/wire"
 	apitypes "github.com/decred/dcrdata/v4/api/types"
 	"github.com/decred/dcrdata/v4/db/agendadb"
 	"github.com/decred/dcrdata/v4/db/dbtypes"
@@ -42,7 +44,7 @@ type DataSourceLite interface {
 	GetBestBlockHash() (string, error)
 	GetBlockHash(idx int64) (string, error)
 	GetBlockHeight(hash string) (int64, error)
-	//Get(idx int) *blockdata.BlockData
+	GetBlockByHash(string) (*wire.MsgBlock, error)
 	GetHeader(idx int) *dcrjson.GetBlockHeaderVerboseResult
 	GetBlockVerbose(idx int, verboseTx bool) *dcrjson.GetBlockVerboseResult
 	GetBlockVerboseByHash(hash string, verboseTx bool) *dcrjson.GetBlockVerboseResult
@@ -441,6 +443,38 @@ func (c *appContext) getBlockHeader(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, blockHeader, c.getIndentQuery(r))
 }
 
+func (c *appContext) getBlockRaw(w http.ResponseWriter, r *http.Request) {
+	hash := c.getBlockHashCtx(r)
+	if hash == "" {
+		http.Error(w, http.StatusText(422), 422)
+		return
+	}
+
+	msgBlock, err := c.BlockData.GetBlockByHash(hash)
+	if err != nil {
+		apiLog.Errorf("Unable to get block %s: %v", hash, err)
+		http.Error(w, http.StatusText(422), 422)
+		return
+	}
+
+	var hexString strings.Builder
+	hexString.Grow(msgBlock.SerializeSize())
+	err = msgBlock.Serialize(hex.NewEncoder(&hexString))
+	if err != nil {
+		apiLog.Errorf("Unable to serialize block %s: %v", hash, err)
+		http.Error(w, http.StatusText(422), 422)
+		return
+	}
+
+	blockRaw := &apitypes.BlockRaw{
+		Height: msgBlock.Header.Height,
+		Hash:   hash,
+		Hex:    hexString.String(),
+	}
+
+	writeJSON(w, blockRaw, c.getIndentQuery(r))
+}
+
 func (c *appContext) getBlockVerbose(w http.ResponseWriter, r *http.Request) {
 	hash := c.getBlockHashCtx(r)
 	if hash == "" {

api/types/apitypes.go

@@ -118,6 +118,13 @@ type BlockID struct {
 	BlockTime   int64  `json:"blocktime"`
 }
 
+// BlockRaw contains the hexadecimal encoded bytes of a serialized block.
+type BlockRaw struct {
+	Height uint32 `json:"height"`
+	Hash   string `json:"hash"`
+	Hex    string `json:"hex"`
+}
+
 // VoutMined appends a best block hash, number of confimations and if a
 // transaction is a coinbase to a transaction output
 type VoutMined struct {

db/dcrsqlite/apisource.go

@@ -491,6 +491,16 @@ func (db *WiredDB) GetBlockVerbose(idx int, verboseTx bool) *dcrjson.GetBlockVer
 func (db *WiredDB) GetBlockVerboseByHash(hash string, verboseTx bool) *dcrjson.GetBlockVerboseResult {
 	return rpcutils.GetBlockVerboseByHash(db.client, hash, verboseTx)
 }
+
+func (db *WiredDB) GetBlockByHash(hash string) (*wire.MsgBlock, error) {
+	blockHash, err := chainhash.NewHashFromStr(hash)
+	if err != nil {
+		log.Errorf("Invalid block hash %s", hash)
+		return nil, err
+	}
+	return db.client.GetBlock(blockHash)
+}
+
 func (db *WiredDB) CoinSupply() (supply *apitypes.CoinSupply) {
 	coinSupply, err := db.client.GetCoinSupply()
 	if err != nil {