Add /blocks , /blocks/{hashOrHeight} APIs (#732)

* Add /blocks , /blocks/{hashOrHeight} api handlers
- Add storage.WalkBlocks func for handlers
- Add resource.Block

* Block cursor as height

* Add  SkipCursor for supporting cursor as height

* Add blocks handler tests

* Add api doc for blocks api

* Default cursor is common.GenesisBlockHeight

* Fix bug about SkipCursor

* Fix test for walk

* Typo

docs/API.md

@@ -9,8 +9,8 @@ SEBAK, the next BOScoin network with ISAAC consensus protocol.
 <!-- partial(API_v1/transactions.md) -->
 
 <!-- include(API_v1/paging.md) -->
+<!-- include(API_v1/models.md) -->
 <!-- include(API_v1/accounts.md) -->
 <!-- include(API_v1/transactions.md) -->
-<!-- include(API_v1/models.md) -->
 <!-- include(API_v1/operations.md) -->
-
+<!-- include(API_v1/blocks.md) -->

docs/API_v1/blocks.md

@@ -0,0 +1,39 @@
+# Group Blocks
+Blocks API
+
+## Blocks [/api/v1/blocks?cursor={cursor}&limit={limit}&reverse={reverse}] 
+
++ Parameters
+    + cursor: `1207` (string, optional)  - a block height as cursor
+    + reverse: `false` (string, optional)
+    + limit: `100` (integer, optional)
+
+### Retrieve blocks [GET]
+
+<p>Retrieve all valid blocks </p>
+
+<p> Streaming mode supported with header "Accept": "text/event-stream" </p>
+
++ Response 200 (application/hal+json; charset=utf-8)
+    + Attributes (Blocks)
+
++ Response 500 (application/problem+json; charset=utf-8)
+    + Attributes (Problem)
+
+
+## Block Details [/api/v1/blocks/{hashOrHeight}]
+
++ Parameters
+    + hashOrHeight: `CLNes5kkg7ozgnHBhpBXHMHFtPKo7z4RF8NZpNGRUB4i` `1207` (string,required) - a block hash or height
+
+### Retrieve a block [GET]
+
+<p> Retrieve a block by the hash or height <p>
+
++ Response 200 (application/hal+json; charset=utf-8)
+    + Attributes (Block)
++ Response 404 (application/problem+json; charset=utf-8)
+    + Attributes (Problem NotFound)
++ Response 500 (application/problem+json; charset=utf-8)
+    + Attributes (Problem)
+

docs/API_v1/models.md

@@ -146,6 +146,50 @@
         + self
             + href: `/api/v1/transactions/7nLuyg8radTExzBM2WhG37AwohBwEySBw4vj2xdtdjAs/operations`
 
+### Blocks
++ _embedded
+    + records (array)
+        + (object):
+            + _links
+                + self
+                    + href: `/api/v1/blocks/AcFpZMr6EhxBuCw3xADUzepa395wmh3c5fo2cyxYCi1q`
+        + confirmed: 2018-11-18T18:44:47.900933000+09:00
+        + hash: `AcFpZMr6EhxBuCw3xADUzepa395wmh3c5fo2cyxYCi1q`
+        + height: 1
+        + prev_block_hash: `J8TQCCtsiLcRZpYtVN3ozCFByd24fjXe2BgodLkeXN7S`,
+        + proposed_time: `2018-04-17T5:07:31.000000000Z`
+        + proposer: `GDIRF4UWPACXPPI4GW7CMTACTCNDIKJEHZK44RITZB4TD3YUM6CCVNGJ`
+        + proposer_transaction: `EQNSFnhzzz3bDpaZQekWPPNtr3kmRs5fUafBYAkHGXRP`
+        + round: 0,
+        + transactions (array)
+            + `BivUS2tYjm1ZYXZNvKqRDa1eyBRTcE3DeuEDJVtuwNcm`
+        + transactions_root: `BR2gsNw5WGjZ6HFPNr8fFAQPu42dqk1P7VVV7p5Efnru`
+        + version: 0
++ _links
+    + next
+        + href: `/api/v1/blocks?cursor=1&limit=100&reverse=false`
+    + prev
+        + href: `/api/v1/blocks?cursor=1&limit=100&reverse=true`
+    + self
+        + href: `/api/v1/blocks`
+
+### Block
++ _links
+    + self
+        + href: `/api/v1/blocks/AcFpZMr6EhxBuCw3xADUzepa395wmh3c5fo2cyxYCi1q`
++ confirmed: 2018-11-18T18:44:47.900933000+09:00
++ hash: `AcFpZMr6EhxBuCw3xADUzepa395wmh3c5fo2cyxYCi1q`
++ height: 3 
++ prev_block_hash: `J8TQCCtsiLcRZpYtVN3ozCFByd24fjXe2BgodLkeXN7S`,
++ proposed_time: `2018-04-17T5:07:31.000000000Z`
++ proposer: `GDIRF4UWPACXPPI4GW7CMTACTCNDIKJEHZK44RITZB4TD3YUM6CCVNGJ`
++ proposer_transaction: `EQNSFnhzzz3bDpaZQekWPPNtr3kmRs5fUafBYAkHGXRP`
++ round: 0
++ transactions (array)
+    + `BivUS2tYjm1ZYXZNvKqRDa1eyBRTcE3DeuEDJVtuwNcm`
++ transactions_root: `BR2gsNw5WGjZ6HFPNr8fFAQPu42dqk1P7VVV7p5Efnru`
++ version: 0
+
 ### Problem
 + status:  500 (number)
 + title: `problem error message`

lib/block/block.go

@@ -70,6 +70,11 @@ func getBlockKeyPrefixHeight(height uint64) string {
 	return fmt.Sprintf("%s%020d", common.BlockPrefixHeight, height)
 }
 
+//GetBlockKeyPrefixHeight returns index key by height. It is used to make cursor as height.
+func GetBlockKeyPrefixHeight(height uint64) string {
+	return getBlockKeyPrefixHeight(height)
+}
+
 func (b Block) NewBlockKeyConfirmed() string {
 	return fmt.Sprintf(
 		"%s%s-%s%s",
@@ -246,3 +251,19 @@ func GetLatestBlock(st *storage.LevelDBBackend) Block {
 
 	return b
 }
+
+func WalkBlocks(st *storage.LevelDBBackend, option *storage.WalkOption, walkFunc func(*Block, []byte) (bool, error)) error {
+	err := st.Walk(common.BlockPrefixHeight, option, func(key, value []byte) (bool, error) {
+		var hash string
+		if err := json.Unmarshal(value, &hash); err != nil {
+			return false, err
+		}
+
+		b, err := GetBlock(st, hash)
+		if err != nil {
+			return false, err
+		}
+		return walkFunc(&b, key)
+	})
+	return err
+}

lib/errors/errors.go

@@ -105,4 +105,5 @@ var (
 	PageQueryLimitMaxExceed                   = NewError(187, "maximum value of limit query parameter exceed")
 	TransactionPoolFull                       = NewError(188, "transaction pool is full")
 	TransactionAlreadyExistsInPool            = NewError(189, "transaction already exists in pool")
+	BadRequestParameter                       = NewError(190, "request parameter is invalid")
 )

lib/network/httputils/httputils.go

@@ -24,6 +24,7 @@ var (
 		errors.BlockTransactionDoesNotExists.Code: http.StatusNotFound,
 		errors.BlockAccountDoesNotExists.Code:     http.StatusNotFound,
 		errors.TransactionPoolFull.Code:           http.StatusLocked,
+		errors.BadRequestParameter.Code:           http.StatusBadRequest,
 	}
 )
 

lib/node/runner/api/api.go

@@ -26,6 +26,8 @@ const (
 	GetTransactionOperationsHandlerPattern = "/transactions/{id}/operations"
 	PostTransactionPattern                 = "/transactions"
 	GetTransactionHistoryHandlerPattern    = "/transactions/{id}/history"
+	GetBlocksHandlerPattern                = "/blocks"
+	GetBlockHandlerPattern                 = "/blocks/{hashOrHeight}"
 	GetNodeInfoPattern                     = "/"
 )
 

lib/node/runner/api/test.go → lib/node/runner/api/base_test.go

@@ -33,6 +33,8 @@ func prepareAPIServer() (*httptest.Server, *storage.LevelDBBackend) {
 	router.HandleFunc(GetAccountHandlerPattern, apiHandler.GetAccountHandler).Methods("GET")
 	router.HandleFunc(GetAccountHandlerPattern, apiHandler.GetAccountHandler).Methods("GET")
 	router.HandleFunc(GetTransactionOperationsHandlerPattern, apiHandler.GetOperationsByTxHashHandler).Methods("GET")
+	router.HandleFunc(GetBlocksHandlerPattern, apiHandler.GetBlocksHandler).Methods("GET")
+	router.HandleFunc(GetBlockHandlerPattern, apiHandler.GetBlockHandler).Methods("GET")
 	ts := httptest.NewServer(router)
 	return ts, storage
 }

lib/node/runner/api/block.go

@@ -0,0 +1,47 @@
+package api
+
+import (
+	"net/http"
+	"strconv"
+
+	"boscoin.io/sebak/lib/block"
+	"boscoin.io/sebak/lib/errors"
+	"boscoin.io/sebak/lib/network/httputils"
+	"boscoin.io/sebak/lib/node/runner/api/resource"
+
+	"github.com/gorilla/mux"
+)
+
+func (api NetworkHandlerAPI) GetBlockHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	hash := vars["hashOrHeight"]
+	if hash == "" {
+		err := errors.BadRequestParameter
+		httputils.WriteJSONError(w, err)
+		return
+	}
+
+	var isHash bool
+	height, err := strconv.ParseUint(hash, 10, 64)
+	if err != nil {
+		isHash = true
+	}
+
+	var res resource.Resource
+	{
+		var b block.Block
+		var err error
+		if isHash {
+			b, err = block.GetBlock(api.storage, hash)
+		} else {
+			b, err = block.GetBlockByHeight(api.storage, height)
+		}
+
+		if err != nil {
+			httputils.WriteJSONError(w, err)
+			return
+		}
+		res = resource.NewBlock(&b)
+	}
+	httputils.MustWriteJSON(w, 200, res)
+}

lib/node/runner/api/block_test.go

@@ -0,0 +1,49 @@
+package api
+
+import (
+	"bufio"
+	"encoding/json"
+	"io/ioutil"
+	"strings"
+	"testing"
+
+	"boscoin.io/sebak/lib/block"
+	"github.com/stretchr/testify/require"
+)
+
+func TestBlockHandler(t *testing.T) {
+	ts, st := prepareAPIServer()
+	defer st.Close()
+	defer ts.Close()
+
+	genesis := block.GetLatestBlock(st)
+
+	reqFunc := func(url string) map[string]interface{} {
+
+		respBody := request(ts, url, false)
+		defer respBody.Close()
+		bs, err := ioutil.ReadAll(bufio.NewReader(respBody))
+		require.NoError(t, err)
+
+		result := make(map[string]interface{})
+		err = json.Unmarshal(bs, &result)
+		require.NoError(t, err)
+
+		return result
+	}
+
+	{
+		url := strings.Replace(GetBlockHandlerPattern, "{hashOrHeight}", "1", 1)
+		res := reqFunc(url)
+		require.Equal(t, res["hash"], genesis.Hash)
+		require.Equal(t, res["transactions_root"], genesis.TransactionsRoot)
+	}
+
+	{
+		url := strings.Replace(GetBlockHandlerPattern, "{hashOrHeight}", genesis.Hash, 1)
+		res := reqFunc(url)
+		require.Equal(t, res["hash"], genesis.Hash)
+		require.Equal(t, res["transactions_root"], genesis.TransactionsRoot)
+	}
+
+}

lib/node/runner/api/blocks.go

@@ -0,0 +1,71 @@
+package api
+
+import (
+	"net/http"
+	"strconv"
+
+	"boscoin.io/sebak/lib/block"
+	"boscoin.io/sebak/lib/common"
+	"boscoin.io/sebak/lib/common/observer"
+	"boscoin.io/sebak/lib/network/httputils"
+	"boscoin.io/sebak/lib/node/runner/api/resource"
+	"boscoin.io/sebak/lib/storage"
+)
+
+func (api NetworkHandlerAPI) GetBlocksHandler(w http.ResponseWriter, r *http.Request) {
+	p, err := NewPageQuery(r)
+	if err != nil {
+		httputils.WriteJSONError(w, err)
+		return
+	}
+
+	var (
+		cursor []byte // cursor as height
+		blocks []resource.Resource
+	)
+
+	var option *storage.WalkOption
+	{
+		height, err := strconv.ParseUint(string(p.Cursor()), 10, 64)
+		if err != nil {
+			height = common.GenesisBlockHeight // default cursor is genesis block height
+		}
+		option = storage.NewWalkOption(block.GetBlockKeyPrefixHeight(height), p.Limit(), p.Reverse(), false)
+		if httputils.IsEventStream(r) {
+			option.Limit = 10
+		}
+	}
+
+	{
+		err := block.WalkBlocks(api.storage, option, func(b *block.Block, key []byte) (next bool, err error) {
+			blocks = append(blocks, resource.NewBlock(b))
+			height := b.Height
+			if height > 1 {
+				if option.Reverse {
+					height--
+				} else {
+					height++
+				}
+			}
+			cursor = []byte(strconv.FormatUint(height, 10))
+			return true, nil
+		})
+		if err != nil {
+			httputils.WriteJSONError(w, err)
+			return
+
+		}
+	}
+
+	if httputils.IsEventStream(r) {
+		es := NewEventStream(w, r, renderEventStream, DefaultContentType)
+		for _, b := range blocks {
+			es.Render(b)
+		}
+		es.Run(observer.BlockObserver, block.EventBlockPrefix)
+		return
+	}
+
+	list := p.ResourceList(blocks, cursor)
+	httputils.MustWriteJSON(w, 200, list)
+}