util/StringFormat: new utility library

Makefile.am

@@ -444,6 +444,7 @@ libutil_a_SOURCES = \
 	src/util/NumberParser.hxx \
 	src/util/MimeType.cxx src/util/MimeType.hxx \
 	src/util/StringBuffer.hxx \
+	src/util/StringFormat.hxx \
 	src/util/StringPointer.hxx \
 	src/util/StringView.cxx src/util/StringView.hxx \
 	src/util/AllocatedString.cxx src/util/AllocatedString.hxx \

src/AudioFormat.cxx

@@ -19,9 +19,9 @@
 
 #include "AudioFormat.hxx"
 #include "util/StringBuffer.hxx"
+#include "util/StringFormat.hxx"
 
 #include <assert.h>
-#include <stdio.h>
 
 void
 AudioFormat::ApplyMask(AudioFormat mask) noexcept
@@ -44,21 +44,16 @@ AudioFormat::ApplyMask(AudioFormat mask) noexcept
 StringBuffer<24>
 ToString(const AudioFormat af) noexcept
 {
-	StringBuffer<24> buffer;
-
 	if (af.format == SampleFormat::DSD && af.sample_rate > 0 &&
 	    af.sample_rate % 44100 == 0) {
 		/* use shortcuts such as "dsd64" which implies the
 		   sample rate */
-		snprintf(buffer.data(), buffer.capacity(), "dsd%u:%u",
+		return StringFormat<24>("dsd%u:%u",
 					af.sample_rate * 8 / 44100,
 					af.channels);
-		return buffer;
 	}
 
-	snprintf(buffer.data(), buffer.capacity(), "%u:%s:%u",
+	return StringFormat<24>("%u:%s:%u",
 				af.sample_rate, sample_format_to_string(af.format),
 				af.channels);
-
-	return buffer;
 }

src/db/plugins/upnp/ContentDirectoryService.cxx

@@ -27,6 +27,7 @@
 #include "util/UriUtil.hxx"
 #include "util/RuntimeError.hxx"
 #include "util/ScopeExit.hxx"
+#include "util/StringFormat.hxx"
 
 #include <stdio.h>
 
@@ -47,10 +48,6 @@ ContentDirectoryService::readDirSlice(UpnpClient_Handle hdl,
 				      unsigned &didreadp,
 				      unsigned &totalp) const
 {
-	// Create request
-	char ofbuf[100], cntbuf[100];
-	sprintf(ofbuf, "%u", offset);
-	sprintf(cntbuf, "%u", count);
 	// Some devices require an empty SortCriteria, else bad params
 	IXML_Document *request =
 		MakeActionHelper("Browse", m_serviceType.c_str(),
@@ -58,8 +55,10 @@ ContentDirectoryService::readDirSlice(UpnpClient_Handle hdl,
 				 "BrowseFlag", "BrowseDirectChildren",
 				 "Filter", "*",
 				 "SortCriteria", "",
-				 "StartingIndex", ofbuf,
-				 "RequestedCount", cntbuf);
+				 "StartingIndex",
+				 StringFormat<32>("%u", offset).c_str(),
+				 "RequestedCount",
+				 StringFormat<32>("%u", count).c_str());
 	if (request == nullptr)
 		throw std::runtime_error("UpnpMakeAction() failed");
 
@@ -112,15 +111,13 @@ ContentDirectoryService::search(UpnpClient_Handle hdl,
 	unsigned offset = 0, total = -1, count;
 
 	do {
-		char ofbuf[100];
-		sprintf(ofbuf, "%d", offset);
-
 		UniqueIxmlDocument request(MakeActionHelper("Search", m_serviceType.c_str(),
 							    "ContainerID", objectId,
 							    "SearchCriteria", ss,
 							    "Filter", "*",
 							    "SortCriteria", "",
-							    "StartingIndex", ofbuf,
+							    "StartingIndex",
+							    StringFormat<32>("%u", offset).c_str(),
 							    "RequestedCount", "0")); // Setting a value here gets twonky into fits
 		if (!request)
 			throw std::runtime_error("UpnpMakeAction() failed");

src/decoder/plugins/GmeDecoderPlugin.cxx

@@ -28,7 +28,7 @@
 #include "fs/Path.hxx"
 #include "fs/AllocatedPath.hxx"
 #include "util/ScopeExit.hxx"
-#include "util/FormatString.hxx"
+#include "util/StringFormat.hxx"
 #include "util/UriUtil.hxx"
 #include "util/Domain.hxx"
 #include "Log.hxx"
@@ -38,7 +38,6 @@
 #include <assert.h>
 #include <stdlib.h>
 #include <string.h>
-#include <stdio.h>
 
 #define SUBTUNE_PREFIX "tune_"
 
@@ -191,18 +190,15 @@ ScanGmeInfo(const gme_info_t &info, unsigned song_num, int track_count,
 		tag_handler_invoke_duration(handler, handler_ctx,
 					    SongTime::FromMS(info.play_length));
 
-	if (track_count > 1) {
-		char track[16];
-		sprintf(track, "%u", song_num + 1);
-		tag_handler_invoke_tag(handler, handler_ctx, TAG_TRACK, track);
-	}
+	if (track_count > 1)
+		tag_handler_invoke_tag(handler, handler_ctx, TAG_TRACK,
+				       StringFormat<16>("%u", song_num + 1));
 
 	if (info.song != nullptr) {
 		if (track_count > 1) {
 			/* start numbering subtunes from 1 */
-			char tag_title[1024];
-			snprintf(tag_title, sizeof(tag_title),
-				 "%s (%u/%d)",
+			const auto tag_title =
+				StringFormat<1024>("%s (%u/%d)",
 						   info.song, song_num + 1,
 						   track_count);
 			tag_handler_invoke_tag(handler, handler_ctx,
@@ -297,9 +293,9 @@ gme_container_scan(Path path_fs)
 		ScanMusicEmu(emu, i,
 			     add_tag_handler, &tag_builder);
 
-		char track_name[64];
-		snprintf(track_name, sizeof(track_name),
-			 SUBTUNE_PREFIX "%03u.%s", i+1, subtune_suffix);
+		const auto track_name =
+			StringFormat<64>(SUBTUNE_PREFIX "%03u.%s", i+1,
+					 subtune_suffix);
 		tail = list.emplace_after(tail, track_name,
 					  tag_builder.Commit());
 	}

src/decoder/plugins/SidplayDecoderPlugin.cxx

@@ -26,7 +26,7 @@
 #include "fs/Path.hxx"
 #include "fs/AllocatedPath.hxx"
 #include "util/Macros.hxx"
-#include "util/FormatString.hxx"
+#include "util/StringFormat.hxx"
 #include "util/Domain.hxx"
 #include "system/ByteOrder.hxx"
 #include "Log.hxx"
@@ -413,9 +413,8 @@ ScanSidTuneInfo(const SidTuneInfo &info, unsigned track, unsigned n_tracks,
 		title = "";
 
 	if (n_tracks > 1) {
-		char tag_title[1024];
-		snprintf(tag_title, sizeof(tag_title),
-			 "%s (%u/%u)",
+		const auto tag_title =
+			StringFormat<1024>("%s (%u/%u)",
 					   title, track, n_tracks);
 		tag_handler_invoke_tag(handler, handler_ctx,
 				       TAG_TITLE, tag_title);
@@ -435,9 +434,8 @@ ScanSidTuneInfo(const SidTuneInfo &info, unsigned track, unsigned n_tracks,
 				       date);
 
 	/* track */
-	char track_buffer[16];
-	sprintf(track_buffer, "%d", track);
-	tag_handler_invoke_tag(handler, handler_ctx, TAG_TRACK, track_buffer);
+	tag_handler_invoke_tag(handler, handler_ctx, TAG_TRACK,
+			       StringFormat<16>("%u", track));
 }
 
 static bool

src/fs/io/FileOutputStream.cxx

@@ -20,6 +20,7 @@
 #include "config.h"
 #include "FileOutputStream.hxx"
 #include "system/Error.hxx"
+#include "util/StringFormat.hxx"
 
 FileOutputStream::FileOutputStream(Path _path, Mode _mode)
 	:path(_path), mode(_mode)
@@ -212,10 +213,9 @@ FileOutputStream::Commit()
 		unlink(GetPath().c_str());
 
 		/* hard-link the temporary file to the final path */
-		char fd_path[64];
-		snprintf(fd_path, sizeof(fd_path), "/proc/self/fd/%d",
-			 fd.Get());
-		if (linkat(AT_FDCWD, fd_path, AT_FDCWD, path.c_str(),
+		if (linkat(AT_FDCWD,
+			   StringFormat<64>("/proc/self/fd/%d", fd.Get()),
+			   AT_FDCWD, path.c_str(),
 			   AT_SYMLINK_FOLLOW) < 0)
 			throw FormatErrno("Failed to commit %s",
 					  path.c_str());

src/input/plugins/CurlInputPlugin.cxx

@@ -34,6 +34,7 @@
 #include "IOThread.hxx"
 #include "util/ASCII.hxx"
 #include "util/StringUtil.hxx"
+#include "util/StringFormat.hxx"
 #include "util/NumberParser.hxx"
 #include "util/RuntimeError.hxx"
 #include "util/Domain.hxx"
@@ -373,13 +374,10 @@ CurlInputStream::InitEasy()
 	if (proxy_port > 0)
 		request->SetOption(CURLOPT_PROXYPORT, (long)proxy_port);
 
-	if (proxy_user != nullptr && proxy_password != nullptr) {
-		char proxy_auth_str[1024];
-		snprintf(proxy_auth_str, sizeof(proxy_auth_str),
-			 "%s:%s",
-			 proxy_user, proxy_password);
-		request->SetOption(CURLOPT_PROXYUSERPWD, proxy_auth_str);
-	}
+	if (proxy_user != nullptr && proxy_password != nullptr)
+		request->SetOption(CURLOPT_PROXYUSERPWD,
+				   StringFormat<1024>("%s:%s", proxy_user,
+						      proxy_password).c_str());
 
 	request->SetOption(CURLOPT_SSL_VERIFYPEER, verify_peer ? 1l : 0l);
 	request->SetOption(CURLOPT_SSL_VERIFYHOST, verify_host ? 2l : 0l);
@@ -416,11 +414,10 @@ CurlInputStream::SeekInternal(offset_type new_offset)
 
 	/* send the "Range" header */
 
-	if (offset > 0) {
-		char range[32];
-		sprintf(range, "%" PRIoffset "-", offset);
-		request->SetOption(CURLOPT_RANGE, range);
-	}
+	if (offset > 0)
+		request->SetOption(CURLOPT_RANGE,
+				   StringFormat<40>("%" PRIoffset "-",
+						    offset).c_str());
 
 	StartRequest();
 }

src/lib/ffmpeg/LogCallback.cxx

@@ -25,6 +25,7 @@
 #include "Domain.hxx"
 #include "LogV.hxx"
 #include "util/Domain.hxx"
+#include "util/StringFormat.hxx"
 
 extern "C" {
 #include <libavutil/log.h>
@@ -57,9 +58,10 @@ FfmpegLogCallback(gcc_unused void *ptr, int level, const char *fmt, va_list vl)
 		cls = *(const AVClass *const*)ptr;
 
 	if (cls != nullptr) {
-		char domain[64];
-		snprintf(domain, sizeof(domain), "%s/%s",
-			 ffmpeg_domain.GetName(), cls->item_name(ptr));
+		const auto domain =
+			StringFormat<64>("%s/%s",
+					 ffmpeg_domain.GetName(),
+					 cls->item_name(ptr));
 		const Domain d(domain);
 		LogFormatV(d, FfmpegImportLogLevel(level), fmt, vl);
 	}

src/output/Init.cxx

@@ -37,6 +37,7 @@
 #include "config/ConfigGlobal.hxx"
 #include "config/Block.hxx"
 #include "util/RuntimeError.hxx"
+#include "util/StringFormat.hxx"
 #include "Log.hxx"
 
 #include <stdexcept>

src/protocol/Ack.hxx

@@ -20,9 +20,9 @@
 #ifndef MPD_ACK_H
 #define MPD_ACK_H
 
-#include <stdexcept>
+#include "util/StringFormat.hxx"
 
-#include <stdio.h>
+#include <stdexcept>
 
 class Domain;
 
@@ -60,9 +60,9 @@ template<typename... Args>
 static inline ProtocolError
 FormatProtocolError(enum ack code, const char *fmt, Args&&... args) noexcept
 {
-	char buffer[256];
-	snprintf(buffer, sizeof(buffer), fmt, std::forward<Args>(args)...);
-	return ProtocolError(code, buffer);
+	return ProtocolError(code,
+			     StringFormat<256>(fmt,
+					       std::forward<Args>(args)...));
 }
 
 #endif

src/storage/plugins/CurlStorage.cxx

@@ -35,6 +35,7 @@
 #include "thread/Cond.hxx"
 #include "util/RuntimeError.hxx"
 #include "util/StringCompare.hxx"
+#include "util/StringFormat.hxx"
 #include "util/TimeParser.hxx"
 #include "util/UriUtil.hxx"
 
@@ -296,9 +297,7 @@ public:
 	{
 		request.SetOption(CURLOPT_CUSTOMREQUEST, "PROPFIND");
 
-		char buffer[40];
-		sprintf(buffer, "depth: %u", depth);
-		request_headers.Append(buffer);
+		request_headers.Append(StringFormat<40>("depth: %u", depth));
 
 		request.SetOption(CURLOPT_HTTPHEADER, request_headers.Get());
 

src/tag/TagHandler.cxx

@@ -21,8 +21,8 @@
 #include "TagHandler.hxx"
 #include "TagBuilder.hxx"
 #include "util/ASCII.hxx"
+#include "util/StringFormat.hxx"
 
-#include <stdio.h>
 #include <stdlib.h>
 
 static void
@@ -42,11 +42,8 @@ add_tag_tag(TagType type, const char *value, void *ctx)
 		/* filter out this extra data and leading zeroes */
 		char *end;
 		unsigned n = strtoul(value, &end, 10);
-		if (value != end) {
-			char s[21];
-			if (snprintf(s, 21, "%u", n) > 0)
-				tag.AddItem(type, s);
-		}
+		if (value != end)
+			tag.AddItem(type, StringFormat<21>("%u", n));
 	} else
 		tag.AddItem(type, value);
 }

src/thread/Name.hxx

@@ -31,7 +31,7 @@
 #endif
 
 #ifdef HAVE_THREAD_NAME
-#  include <stdio.h>
+#include "util/StringFormat.hxx"
 #endif
 
 static inline void
@@ -59,9 +59,7 @@ static inline void
 FormatThreadName(const char *fmt, gcc_unused Args&&... args)
 {
 #ifdef HAVE_THREAD_NAME
-	char buffer[16];
-	snprintf(buffer, sizeof(buffer), fmt, args...);
-	SetThreadName(buffer);
+	SetThreadName(StringFormat<16>(fmt, args...));
 #else
 	(void)fmt;
 #endif

src/util/StringFormat.hxx

+/*
+ * Copyright (C) 2010-2015 Max Kellermann <max.kellermann@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef STRING_FORMAT_HXX
+#define STRING_FORMAT_HXX
+
+#include "StringBuffer.hxx"
+
+#include <stdio.h>
+
+template<typename... Args>
+static inline void
+StringFormat(char *buffer, size_t size,
+	     const char *fmt, Args&&... args) noexcept
+{
+	snprintf(buffer, size, fmt, args...);
+}
+
+template<size_t CAPACITY, typename... Args>
+static inline void
+StringFormat(StringBuffer<CAPACITY> &buffer,
+	     const char *fmt, Args&&... args) noexcept
+{
+	StringFormat(buffer.data(), buffer.capacity(), fmt, args...);
+}
+
+template<size_t CAPACITY, typename... Args>
+static inline StringBuffer<CAPACITY>
+StringFormat(const char *fmt, Args&&... args) noexcept
+{
+	StringBuffer<CAPACITY> result;
+	StringFormat(result, fmt, args...);
+	return result;
+}
+
+template<typename... Args>
+static inline void
+StringFormatUnsafe(char *buffer, const char *fmt, Args&&... args) noexcept
+{
+	sprintf(buffer, fmt, args...);
+}
+
+#endif