From 68858f950497e50caa9f4ab27915fb066a6f4c3b Mon Sep 17 00:00:00 2001
From: Alex Aizman <alex.aizman@gmail.com>
Date: Sun, 8 Sep 2024 15:33:34 -0400
Subject: [PATCH] add write-xid (micro-optimizations)

Signed-off-by: Alex Aizman <alex.aizman@gmail.com>
---
 ais/htcommon.go      |  8 ++++++++
 ais/proxy.go         | 17 +++++++++--------
 ais/prxbsumm.go      |  4 +---
 ais/prxclu.go        | 14 ++++----------
 ais/target.go        |  4 ++--
 ais/tgtetl.go        |  4 +---
 ais/tgtxact.go       |  6 ++----
 ext/dsort/handler.go |  3 ++-
 8 files changed, 29 insertions(+), 31 deletions(-)

diff --git a/ais/htcommon.go b/ais/htcommon.go
index 01055d70dc3..b2168750738 100644
--- a/ais/htcommon.go
+++ b/ais/htcommon.go
@@ -17,6 +17,7 @@ import (
 	"net/url"
 	"os"
 	rdebug "runtime/debug"
+	"strconv"
 	"strings"
 	"sync"
 	"syscall"
@@ -831,6 +832,13 @@ func apiReqFree(a *apiRequest) {
 // misc helpers
 //
 
+// http response: xaction ID most of the time but may be any string
+func writeXid(w http.ResponseWriter, xid string) {
+	debug.Assert(xid != "")
+	w.Header().Set(cos.HdrContentLength, strconv.Itoa(len(xid)))
+	w.Write(cos.UnsafeB(xid))
+}
+
 func newBckFromQ(bckName string, query url.Values, dpq *dpq) (*meta.Bck, error) {
 	bck := _bckFromQ(bckName, query, dpq)
 	normp, err := cmn.NormalizeProvider(bck.Provider)
diff --git a/ais/proxy.go b/ais/proxy.go
index c979fd16520..3179d5189b3 100644
--- a/ais/proxy.go
+++ b/ais/proxy.go
@@ -954,8 +954,7 @@ func (p *proxy) httpbckdelete(w http.ResponseWriter, r *http.Request, apireq *ap
 			p.writeErr(w, r, err)
 			return
 		}
-		w.Header().Set(cos.HdrContentLength, strconv.Itoa(len(xid)))
-		w.Write([]byte(xid))
+		writeXid(w, xid)
 	default:
 		p.writeErrAct(w, r, msg.Action)
 	}
@@ -1182,8 +1181,7 @@ func (p *proxy) httpbckput(w http.ResponseWriter, r *http.Request) {
 		}
 		xid, err := p.createArchMultiObj(bckFrom, bckTo, msg)
 		if err == nil {
-			w.Header().Set(cos.HdrContentLength, strconv.Itoa(len(xid)))
-			w.Write([]byte(xid))
+			writeXid(w, xid)
 		} else {
 			p.writeErr(w, r, err)
 		}
@@ -1449,8 +1447,7 @@ func (p *proxy) _bckpost(w http.ResponseWriter, r *http.Request, msg *apc.ActMsg
 	}
 
 	debug.Assertf(xact.IsValidUUID(xid) || strings.IndexByte(xid, ',') > 0, "%q: %q", msg.Action, xid)
-	w.Header().Set(cos.HdrContentLength, strconv.Itoa(len(xid)))
-	w.Write([]byte(xid))
+	writeXid(w, xid)
 }
 
 // init existing or create remote
@@ -1840,7 +1837,9 @@ func (p *proxy) httpobjpost(w http.ResponseWriter, r *http.Request, apireq *apiR
 			p.writeErr(w, r, err)
 			return
 		}
-		w.Write([]byte(xid))
+		if xid != "" {
+			writeXid(w, xid)
+		}
 	case apc.ActBlobDl:
 		if err := p.checkAccess(w, r, bck, apc.AccessRW); err != nil {
 			return
@@ -2051,7 +2050,9 @@ func (p *proxy) httpbckpatch(w http.ResponseWriter, r *http.Request, apireq *api
 		p.writeErr(w, r, err)
 		return
 	}
-	w.Write([]byte(xid))
+	if xid != "" {
+		writeXid(w, xid)
+	}
 }
 
 // HEAD /v1/objects/bucket-name/object-name
diff --git a/ais/prxbsumm.go b/ais/prxbsumm.go
index f78ff29dfa6..6eb85164c98 100644
--- a/ais/prxbsumm.go
+++ b/ais/prxbsumm.go
@@ -7,7 +7,6 @@ package ais
 import (
 	"net/http"
 	"net/url"
-	"strconv"
 
 	"github.com/NVIDIA/aistore/api/apc"
 	"github.com/NVIDIA/aistore/cmn"
@@ -32,8 +31,7 @@ func (p *proxy) bsummact(w http.ResponseWriter, r *http.Request, qbck *cmn.Query
 			p.writeErr(w, r, err)
 		} else {
 			w.WriteHeader(http.StatusAccepted)
-			w.Header().Set(cos.HdrContentLength, strconv.Itoa(len(msg.UUID)))
-			w.Write([]byte(msg.UUID))
+			writeXid(w, msg.UUID)
 		}
 		return
 	}
diff --git a/ais/prxclu.go b/ais/prxclu.go
index 7bb2b4f990f..63ed9c5e454 100644
--- a/ais/prxclu.go
+++ b/ais/prxclu.go
@@ -1264,9 +1264,7 @@ func (p *proxy) xstart(w http.ResponseWriter, r *http.Request, msg *apc.ActMsg)
 		smap := p.owner.smap.get()
 		nl := xact.NewXactNL(xargs.ID, xargs.Kind, &smap.Smap, nil)
 		p.ic.registerEqual(regIC{smap: smap, nl: nl})
-
-		w.Header().Set(cos.HdrContentLength, strconv.Itoa(len(xargs.ID)))
-		w.Write([]byte(xargs.ID))
+		writeXid(w, xargs.ID)
 	}
 }
 
@@ -1362,9 +1360,7 @@ func (p *proxy) rebalanceCluster(w http.ResponseWriter, r *http.Request, msg *ap
 		p.writeErr(w, r, err)
 		return
 	}
-	debug.Assert(rmdCtx.rebID != "")
-	w.Header().Set(cos.HdrContentLength, strconv.Itoa(len(rmdCtx.rebID)))
-	w.Write([]byte(rmdCtx.rebID))
+	writeXid(w, rmdCtx.rebID)
 }
 
 func (p *proxy) sendOwnTbl(w http.ResponseWriter, r *http.Request, msg *apc.ActMsg) {
@@ -1509,8 +1505,7 @@ func (p *proxy) rmNode(w http.ResponseWriter, r *http.Request, msg *apc.ActMsg)
 			return
 		}
 		if rebID != "" {
-			w.Header().Set(cos.HdrContentLength, strconv.Itoa(len(rebID)))
-			w.Write(cos.UnsafeB(rebID))
+			writeXid(w, rebID)
 		}
 	}
 }
@@ -1651,8 +1646,7 @@ func (p *proxy) stopMaintenance(w http.ResponseWriter, r *http.Request, msg *apc
 		return
 	}
 	if rebID != "" {
-		w.Header().Set(cos.HdrContentLength, strconv.Itoa(len(rebID)))
-		w.Write(cos.UnsafeB(rebID))
+		writeXid(w, rebID)
 	}
 }
 
diff --git a/ais/target.go b/ais/target.go
index 5d51b8e609f..014c5df78d4 100644
--- a/ais/target.go
+++ b/ais/target.go
@@ -998,8 +998,8 @@ func (t *target) httpobjpost(w http.ResponseWriter, r *http.Request, apireq *api
 		}
 		if xid, _, err = t.blobdl(args, nil /*oa*/); xid != "" {
 			debug.AssertNoErr(err)
-			w.Header().Set(cos.HdrContentLength, strconv.Itoa(len(xid)))
-			w.Write([]byte(xid))
+			writeXid(w, xid)
+
 			// lom is eventually freed by x-blob
 		}
 	default:
diff --git a/ais/tgtetl.go b/ais/tgtetl.go
index eb62f6cc20c..46f216b5822 100644
--- a/ais/tgtetl.go
+++ b/ais/tgtetl.go
@@ -8,7 +8,6 @@ import (
 	"fmt"
 	"net/http"
 	"net/url"
-	"strconv"
 
 	"github.com/NVIDIA/aistore/api/apc"
 	"github.com/NVIDIA/aistore/cmn"
@@ -196,8 +195,7 @@ func (t *target) healthETL(w http.ResponseWriter, r *http.Request, etlName strin
 		}
 		return
 	}
-	w.Header().Set(cos.HdrContentLength, strconv.Itoa(len(health)))
-	w.Write([]byte(health))
+	writeXid(w, health)
 }
 
 func (t *target) metricsETL(w http.ResponseWriter, r *http.Request, etlName string) {
diff --git a/ais/tgtxact.go b/ais/tgtxact.go
index e201432d686..c274eabe970 100644
--- a/ais/tgtxact.go
+++ b/ais/tgtxact.go
@@ -7,7 +7,6 @@ package ais
 import (
 	"fmt"
 	"net/http"
-	"strconv"
 	"sync"
 
 	"github.com/NVIDIA/aistore/api/apc"
@@ -132,9 +131,8 @@ func (t *target) httpxput(w http.ResponseWriter, r *http.Request) {
 			t.writeErr(w, r, err)
 			return
 		}
-		if l := len(xid); l > 0 {
-			w.Header().Set(cos.HdrContentLength, strconv.Itoa(l))
-			w.Write([]byte(xid))
+		if xid != "" {
+			writeXid(w, xid)
 		}
 	case apc.ActXactStop:
 		debug.Assert(xact.IsValidKind(xargs.Kind) || xact.IsValidUUID(xargs.ID), xargs.String())
diff --git a/ext/dsort/handler.go b/ext/dsort/handler.go
index 1ce45cb240c..f91f34ea4fb 100644
--- a/ext/dsort/handler.go
+++ b/ext/dsort/handler.go
@@ -102,7 +102,8 @@ func PstartHandler(w http.ResponseWriter, r *http.Request, parsc *ParsedReq) {
 		return
 	}
 
-	w.Write([]byte(managerUUID))
+	w.Header().Set(cos.HdrContentLength, strconv.Itoa(len(managerUUID)))
+	w.Write(cos.UnsafeB(managerUUID))
 }
 
 func _handleResp(w http.ResponseWriter, r *http.Request, smap *meta.Smap, managerUUID string, responses []response) error {