(svn r15126) -Feature: downloading content from a central server (content.openttd.org) where authors can upload they NewGRFS/AI etc. This should make joining servers that use only NewGRFs that are distributed via this system easier as the players can download the NewGRFs from in the game. It should also make it easier to see whether there are updates for NewGRFs and make the necessary updates.

3 files changed, 144 insertions, 1 deletions

diff --git a/src/ai/ai.hpp b/src/ai/ai.hpp
index c1a700f75..96dc93317 100644
--- a/src/ai/ai.hpp
+++ b/src/ai/ai.hpp
@@ -111,7 +111,9 @@ public:
 	static AIInfo *FindInfo(const char *name, int version);
 	static bool ImportLibrary(const char *library, const char *class_name, int version, HSQUIRRELVM vm);
 	static void Rescan();
-
+#if defined(ENABLE_NETWORK)
+	static bool HasAI(const struct ContentInfo *ci, bool md5sum);
+#endif
 private:
 	static uint frame_counter;
 	static class AIScanner *ai_scanner;
diff --git a/src/ai/ai_scanner.cpp b/src/ai/ai_scanner.cpp
index 11f4cdafd..be0dfa59d 100644
--- a/src/ai/ai_scanner.cpp
+++ b/src/ai/ai_scanner.cpp
@@ -416,3 +416,141 @@ char *AIScanner::GetAIConsoleList(char *p, const char *last)
 
 	return p;
 }
+
+#if defined(ENABLE_NETWORK)
+#include "../network/network_content.h"
+#include "../md5.h"
+#include "../tar_type.h"
+
+/** Helper for creating a MD5sum of all files within of an AI. */
+struct AIFileChecksumCreator : FileScanner {
+	byte md5sum[16]; ///< The final md5sum
+
+	/**
+	 * Initialise the md5sum to be all zeroes,
+	 * so we can easily xor the data.
+	 */
+	AIFileChecksumCreator()
+	{
+		memset(this->md5sum, 0, sizeof(this->md5sum));
+	}
+
+	/* Add the file and calculate the md5 sum. */
+	virtual bool AddFile(const char *filename, size_t basepath_length)
+	{
+		Md5 checksum;
+		uint8 buffer[1024];
+		size_t len, size;
+		byte tmp_md5sum[16];
+
+		/* Open the file ... */
+		FILE *f = FioFOpenFile(filename, "rb", DATA_DIR, &size);
+		if (f == NULL) return false;
+
+		/* ... calculate md5sum... */
+		while ((len = fread(buffer, 1, (size > sizeof(buffer)) ? sizeof(buffer) : size, f)) != 0 && size != 0) {
+			size -= len;
+			checksum.Append(buffer, len);
+		}
+		checksum.Finish(tmp_md5sum);
+
+		FioFCloseFile(f);
+
+		/* ... and xor it to the overall md5sum. */
+		for (uint i = 0; i < sizeof(md5sum); i++) this->md5sum[i] ^= tmp_md5sum[i];
+
+		return true;
+	}
+};
+
+/**
+ * Check whether the AI given in info is the same as in ci based
+ * on the shortname and md5 sum.
+ * @param ci   the information to compare to
+ * @param md5sum whether to check the MD5 checksum
+ * @param info the AI to get the shortname and md5 sum from
+ * @return true iff they're the same
+ */
+static bool IsSameAI(const ContentInfo *ci, bool md5sum, AIFileInfo *info)
+{
+	uint32 id = 0;
+	const char *str = info->GetShortName();
+	for (int j = 0; j < 4 && *str != '\0'; j++, str++) id |= *str << (8 * j);
+
+	if (id != ci->unique_id) return false;
+	if (!md5sum) return true;
+
+	AIFileChecksumCreator checksum;
+	char path[MAX_PATH];
+	strecpy(path, info->GetMainScript(), lastof(path));
+	/* There'll always be at least 2 path separator characters in an AI's
+	 * main script name as the search algorithm requires the main script to
+	 * be in a subdirectory of the AI directory; so ai/<path>/main.nut. */
+	*strrchr(path, PATHSEPCHAR) = '\0';
+	*strrchr(path, PATHSEPCHAR) = '\0';
+	TarList::iterator iter = _tar_list.find(path);
+
+	if (iter != _tar_list.end()) {
+		/* The main script is in a tar file, so find all files that
+		 * are in the same tar and add them to the MD5 checksumming. */
+		TarFileList::iterator tar;
+		FOR_ALL_TARS(tar) {
+			/* Not in the same tar. */
+			if (tar->second.tar_filename != iter->first) continue;
+
+			/* Check the extension. */
+			const char *ext = strrchr(tar->first.c_str(), '.');
+			if (ext == NULL || strcasecmp(ext, ".nut") != 0) continue;
+
+			/* Create the full path name, */
+			seprintf(path, lastof(path), "%s%c%s", tar->second.tar_filename, PATHSEPCHAR, tar->first.c_str());
+			checksum.AddFile(path, 0);
+		}
+	} else {
+		/* Add the path sep char back when searching a directory, so we are
+		 * in the actual directory. */
+		path[strlen(path)] = PATHSEPCHAR;
+		checksum.Scan(".nut", path);
+	}
+
+	return memcmp(ci->md5sum, checksum.md5sum, sizeof(ci->md5sum)) == 0;
+}
+
+/**
+ * Check whether we have an AI (library) with the exact characteristics as ci.
+ * @param ci the characteristics to search on (shortname and md5sum)
+ * @param md5sum whether to check the MD5 checksum
+ * @return true iff we have an AI (library) matching.
+ */
+bool AIScanner::HasAI(const ContentInfo *ci, bool md5sum)
+{
+	switch (ci->type) {
+		case CONTENT_TYPE_AI:
+			for (AIInfoList::iterator it = this->info_list.begin(); it != this->info_list.end(); it++) {
+				if (IsSameAI(ci, md5sum, (*it).second)) return true;
+			}
+			return false;
+
+		case CONTENT_TYPE_AI_LIBRARY:
+			for (AILibraryList::iterator it = this->library_list.begin(); it != this->library_list.end(); it++) {
+				if (IsSameAI(ci, md5sum, (*it).second)) return true;
+			}
+			return false;
+
+		default:
+			NOT_REACHED();
+	}
+}
+
+/**
+ * Check whether we have an AI (library) with the exact characteristics as ci.
+ * @param ci the characteristics to search on (shortname and md5sum)
+ * @param md5sum whether to check the MD5 checksum
+ * @return true iff we have an AI (library) matching.
+ */
+/*static */ bool AI::HasAI(const ContentInfo *ci, bool md5sum)
+{
+	return AI::ai_scanner->HasAI(ci, md5sum);
+}
+
+#endif /* ENABLE_NETWORK */
diff --git a/src/ai/ai_scanner.hpp b/src/ai/ai_scanner.hpp
index 3e82e4682..e79d8ec1d 100644
--- a/src/ai/ai_scanner.hpp
+++ b/src/ai/ai_scanner.hpp
@@ -64,6 +64,9 @@ public:
 	 */
 	void RescanAIDir();
 
+#if defined(ENABLE_NETWORK)
+  bool HasAI(const struct ContentInfo *ci, bool md5sum);
+#endif
 private:
 	typedef std::map<const char *, class AILibrary *, ltstr> AILibraryList;