[winpr,timezone] encapsulate timezonemap

winpr/libwinpr/timezone/TimeZoneNameMap.h

@@ -41,9 +41,7 @@ typedef struct
 	const char* Iana;
 } TimeZoneNameMapEntry;
 
-extern const TimeZoneNameMapEntry TimeZoneNameMap[];
-extern const size_t TimeZoneNameMapSize;
-
+const TimeZoneNameMapEntry* TimeZoneGetAt(size_t index);
 const char* TimeZoneIanaToWindows(const char* iana, TimeZoneNameType type);
 
 #endif

winpr/libwinpr/timezone/TimeZoneNameMapUtils.c

@@ -20,6 +20,7 @@
 #include <winpr/config.h>
 #include <winpr/assert.h>
 #include <winpr/string.h>
+#include <winpr/synch.h>
 
 #include <string.h>
 
@@ -31,6 +32,36 @@
 
 #include "TimeZoneNameMap.h"
 
+typedef struct
+{
+	size_t count;
+	TimeZoneNameMapEntry* entries;
+} TimeZoneNameMapContext;
+
+static BOOL CALLBACK load_timezones(PINIT_ONCE once, PVOID param, PVOID* pvcontext)
+{
+	// Do not expose these, only used internally.
+	extern const TimeZoneNameMapEntry TimeZoneNameMap[];
+	extern const size_t TimeZoneNameMapSize;
+
+	TimeZoneNameMapContext* context = pvcontext;
+	WINPR_ASSERT(context);
+
+	context->count = TimeZoneNameMapSize;
+	context->entries = TimeZoneNameMap;
+}
+
+const TimeZoneNameMapEntry* TimeZoneGetAt(size_t index)
+{
+	static INIT_ONCE init_guard = INIT_ONCE_STATIC_INIT;
+	static TimeZoneNameMapContext context = { 0 };
+
+	InitOnceExecuteOnce(&init_guard, load_timezones, NULL, &context);
+	if (index >= context.count)
+		return NULL;
+	return &context.entries[index];
+}
+
 static const char* return_type(const TimeZoneNameMapEntry* entry, TimeZoneNameType type)
 {
 	WINPR_ASSERT(entry);
@@ -51,6 +82,37 @@ static const char* return_type(const TimeZoneNameMapEntry* entry, TimeZoneNameTy
 	}
 }
 
+static BOOL iana_cmp(const TimeZoneNameMapEntry* entry, const char* iana)
+{
+	if (!entry || !iana || !entry->Iana)
+		return FALSE;
+	return strcmp(iana, entry->Iana) == 0;
+}
+
+static BOOL id_cmp(const TimeZoneNameMapEntry* entry, const char* id)
+{
+	if (!entry || !id || !entry->Id)
+		return FALSE;
+	return strcmp(id, entry->Id) == 0;
+}
+
+static const char* get_for_type(const char* val, TimeZoneNameType type,
+                                BOOL (*cmp)(const TimeZoneNameMapEntry*, const char*))
+{
+	WINPR_ASSERT(val);
+	WINPR_ASSERT(cmp);
+
+	size_t index = 0;
+	while (TRUE)
+	{
+		const TimeZoneNameMapEntry* entry = TimeZoneGetAt(index++);
+		if (!entry)
+			return NULL;
+		if (cmp(entry, val))
+			return return_type(entry, type);
+	}
+}
+
 #if defined(WITH_TIMEZONE_ICU)
 static char* get_wzid_icu(const UChar* utzid, size_t utzid_len)
 {
@@ -88,21 +150,11 @@ static char* get(const char* iana)
 
 static const char* map_fallback(const char* iana, TimeZoneNameType type)
 {
-	const char* res = NULL;
 	char* wzid = get(iana);
 	if (!wzid)
 		return NULL;
 
-	for (size_t x = 0; x < TimeZoneNameMapSize; x++)
-	{
-		const TimeZoneNameMapEntry* entry = &TimeZoneNameMap[x];
-		if (strcmp(wzid, entry->Id) == 0)
-		{
-			res = return_type(entry, type);
-			break;
-		}
-	}
-
+	const char* res = get_for_type(wzid, type, id_cmp);
 	free(wzid);
 	return res;
 }
@@ -149,22 +201,13 @@ const char* TimeZoneIanaToWindows(const char* iana, TimeZoneNameType type)
 	if (!iana)
 		return NULL;
 
-	for (size_t x = 0; x < TimeZoneNameMapSize; x++)
-	{
-		const TimeZoneNameMapEntry* entry = &TimeZoneNameMap[x];
-		if (strcmp(iana, entry->Iana) == 0)
-			return return_type(entry, type);
-	}
+	const char* val = get_for_type(iana, type, iana_cmp);
+	if (val)
+		return val;
 
 	const char* wzid = map_fallback(iana, type);
 	if (!wzid)
 		return NULL;
 
-	for (size_t x = 0; x < TimeZoneNameMapSize; x++)
-	{
-		const TimeZoneNameMapEntry* entry = &TimeZoneNameMap[x];
-		if (strcmp(wzid, entry->Id) == 0)
-			return return_type(entry, type);
-	}
-	return NULL;
+	return get_for_type(wzid, type, id_cmp);
 }

winpr/libwinpr/timezone/timezone.c

@@ -853,10 +853,10 @@ DWORD EnumDynamicTimeZoneInformation(const DWORD dwIndex,
 	const DYNAMIC_TIME_ZONE_INFORMATION empty = { 0 };
 	*lpTimeZoneInformation = empty;
 
-	if (dwIndex >= TimeZoneNameMapSize)
+	const TimeZoneNameMapEntry* entry = TimeZoneGetAt(dwIndex);
+	if (!entry)
 		return ERROR_NO_MORE_ITEMS;
 
-	const TimeZoneNameMapEntry* entry = &TimeZoneNameMap[dwIndex];
 	if (entry->DaylightName)
 		ConvertUtf8ToWChar(entry->DaylightName, lpTimeZoneInformation->DaylightName,
 		                   ARRAYSIZE(lpTimeZoneInformation->DaylightName));