From 6e1ee9474491096b6b7bf1c55af00972c3ba0e61 Mon Sep 17 00:00:00 2001
From: Dmitry Stogov <dmitry@zend.com>
Date: Wed, 25 Oct 2017 19:04:16 +0300
Subject: [PATCH] Reduce smart_string related reallocations and make them Zend
 MM friendly.

---
 Zend/zend_smart_str.c    | 41 +++++++++++++++++++++++++++++++++++++
 Zend/zend_smart_string.h | 44 ++++++++--------------------------------
 2 files changed, 50 insertions(+), 35 deletions(-)

diff --git a/Zend/zend_smart_str.c b/Zend/zend_smart_str.c
index b020fddbaa..8f142854d2 100644
--- a/Zend/zend_smart_str.c
+++ b/Zend/zend_smart_str.c
@@ -18,6 +18,7 @@
 
 #include <zend.h>
 #include "zend_smart_str.h"
+#include "zend_smart_string.h"
 
 #define SMART_STR_OVERHEAD (ZEND_MM_OVERHEAD + _ZSTR_HEADER_SIZE)
 
@@ -125,6 +126,46 @@ ZEND_API void ZEND_FASTCALL smart_str_append_printf(smart_str *dest, const char
 	va_end(arg);
 }
 
+#define SMART_STRING_START_SIZE 255
+#define SMART_STRING_PREALLOC   128
+#define SMART_STRING_PAGE       4096
+
+ZEND_API void ZEND_FASTCALL _smart_string_alloc_persistent(smart_string *str, size_t len)
+{
+	if (!str->c) {
+		str->len = 0;
+		str->a = len <= SMART_STRING_START_SIZE
+				? SMART_STRING_START_SIZE
+				: (ZEND_MM_ALIGNED_SIZE_EX(len + SMART_STRING_PREALLOC, SMART_STRING_PAGE) - 1);
+		str->c = malloc(str->a + 1);
+	} else {
+		if (UNEXPECTED((size_t) len > SIZE_MAX - str->len)) {
+			zend_error(E_ERROR, "String size overflow");
+		}
+		len += str->len;
+		str->a = ZEND_MM_ALIGNED_SIZE_EX(len + SMART_STRING_PREALLOC, SMART_STRING_PAGE) - 1;
+		str->c = realloc(str->c, str->a + 1);
+	}
+}
+
+ZEND_API void ZEND_FASTCALL _smart_string_alloc(smart_string *str, size_t len)
+{
+	if (!str->c) {
+		str->len = 0;
+		str->a = len <= SMART_STRING_START_SIZE
+				? SMART_STRING_START_SIZE
+				: (ZEND_MM_ALIGNED_SIZE_EX(len + SMART_STRING_PREALLOC, SMART_STRING_PAGE) - 1);
+		str->c = emalloc(str->a + 1);
+	} else {
+		if (UNEXPECTED((size_t) len > SIZE_MAX - str->len)) {
+			zend_error(E_ERROR, "String size overflow");
+		}
+		len += str->len;
+		str->a = ZEND_MM_ALIGNED_SIZE_EX(len + SMART_STRING_PREALLOC, SMART_STRING_PAGE) - 1;
+		str->c = erealloc(str->c, str->a + 1);
+	}
+}
+
 /*
  * Local variables:
  * tab-width: 4
diff --git a/Zend/zend_smart_string.h b/Zend/zend_smart_string.h
index 12d755ee41..464e58e520 100644
--- a/Zend/zend_smart_string.h
+++ b/Zend/zend_smart_string.h
@@ -25,26 +25,7 @@
 #include "zend_smart_string_public.h"
 
 #include <stdlib.h>
-#ifndef SMART_STR_USE_REALLOC
 #include <zend.h>
-#endif
-
-#ifndef SMART_STRING_PREALLOC
-#define SMART_STRING_PREALLOC 128
-#endif
-
-#ifndef SMART_STRING_START_SIZE
-#define SMART_STRING_START_SIZE 78
-#endif
-
-#ifdef SMART_STRING_USE_REALLOC
-#define SMART_STRING_REALLOC(a,b,c) realloc((a),(b))
-#else
-#define SMART_STRING_REALLOC(a,b,c) perealloc((a),(b),(c))
-#endif
-
-#define SMART_STRING_DO_REALLOC(d, what) \
-	(d)->c = (char *) SMART_STRING_REALLOC((d)->c, (d)->a + 1, (what))
 
 /* wrapper */
 
@@ -71,25 +52,18 @@
 #define smart_string_append_unsigned(str, val) \
 	smart_string_append_unsigned_ex((str), (val), 0)
 
+ZEND_API void ZEND_FASTCALL _smart_string_alloc_persistent(smart_string *str, size_t len);
+ZEND_API void ZEND_FASTCALL _smart_string_alloc(smart_string *str, size_t len);
+
 static zend_always_inline size_t smart_string_alloc(smart_string *str, size_t len, zend_bool persistent) {
-	if (!str->c) {
-		str->len = 0;
-		str->a = len < SMART_STRING_START_SIZE
-				? SMART_STRING_START_SIZE
-				: len + SMART_STRING_PREALLOC;
-		SMART_STRING_DO_REALLOC(str, persistent);
-		return len;
-	} else {
-		if (UNEXPECTED((size_t) len > SIZE_MAX - str->len)) {
-			zend_error(E_ERROR, "String size overflow");
-		}
-		len += str->len;
-		if (UNEXPECTED(len >= str->a)) {
-			str->a = len + SMART_STRING_PREALLOC;
-			SMART_STRING_DO_REALLOC(str, persistent);
+	if (UNEXPECTED(!str->c) || UNEXPECTED(len >= str->a - str->len)) {
+		if (persistent) {
+			_smart_string_alloc_persistent(str, len);
+		} else {
+			_smart_string_alloc(str, len);
 		}
 	}
-	return len;
+	return str->len + len;
 }
 
 static zend_always_inline void smart_string_free_ex(smart_string *str, zend_bool persistent) {
-- 
2.50.1