[ntk/apt.git] / methods / rred.cc

// Includes									/*{{{*/
#include <apt-pkg/fileutl.h>
#include <apt-pkg/mmap.h>
#include <apt-pkg/error.h>
#include <apt-pkg/acquire-method.h>
#include <apt-pkg/strutl.h>
#include <apt-pkg/hashes.h>

#include <sys/stat.h>
#include <sys/uio.h>
#include <unistd.h>
#include <utime.h>
#include <stdio.h>
#include <errno.h>
#include <apti18n.h>
										/*}}}*/
/** \brief RredMethod - ed-style incremential patch method			{{{
 *
 *  This method implements a patch functionality similar to "patch --ed" that is
 *  used by the "tiffany" incremental packages download stuff. It differs from
 *  "ed" insofar that it is way more restricted (and therefore secure).
 *  The currently supported ed commands are "<em>c</em>hange", "<em>a</em>dd" and
 *  "<em>d</em>elete" (diff doesn't output any other).
 *  Additionally the records must be reverse sorted by line number and
 *  may not overlap (diff *seems* to produce this kind of output).
 * */
class RredMethod : public pkgAcqMethod {
	bool Debug;
	// the size of this doesn't really matter (except for performance)
	const static int BUF_SIZE = 1024;
	// the supported ed commands
	enum Mode {MODE_CHANGED='c', MODE_DELETED='d', MODE_ADDED='a'};
	// return values
	enum State {ED_OK, ED_ORDERING, ED_PARSER, ED_FAILURE, MMAP_FAILED};

	State applyFile(FILE *ed_cmds, FILE *in_file, FILE *out_file,
	             unsigned long &line, char *buffer, Hashes *hash) const;
	void ignoreLineInFile(FILE *fin, char *buffer) const;
	void copyLinesFromFileToFile(FILE *fin, FILE *fout, unsigned int lines,
	                            Hashes *hash, char *buffer) const;

	State patchFile(FileFd &Patch, FileFd &From, FileFd &out_file, Hashes *hash) const;
	State patchMMap(FileFd &Patch, FileFd &From, FileFd &out_file, Hashes *hash) const;

protected:
	// the methods main method
	virtual bool Fetch(FetchItem *Itm);

public:
	RredMethod() : pkgAcqMethod("1.1",SingleInstance | SendConfig) {};
};
										/*}}}*/
/** \brief applyFile - in reverse order with a tail recursion			{{{
 *
 *  As it is expected that the commands are in reversed order in the patch file
 *  we check in the first half if the command is valid, but doesn't execute it
 *  and move a step deeper. After reaching the end of the file we apply the
 *  patches in the correct order: last found command first.
 *
 *  \param ed_cmds patch file to apply
 *  \param in_file base file we want to patch
 *  \param out_file file to write the patched result to
 *  \param line of command operation
 *  \param buffer internal used read/write buffer
 *  \param hash the created file for correctness
 *  \return the success State of the ed command executor
 */
RredMethod::State RredMethod::applyFile(FILE *ed_cmds, FILE *in_file, FILE *out_file,
			unsigned long &line, char *buffer, Hashes *hash) const {
	// get the current command and parse it
	if (fgets(buffer, BUF_SIZE, ed_cmds) == NULL) {
		if (Debug == true)
			std::clog << "rred: encounter end of file - we can start patching now." << std::endl;
		line = 0;
		return ED_OK;
	}

	// parse in the effected linenumbers
	char* idx;
	errno=0;
	unsigned long const startline = strtol(buffer, &idx, 10);
	if (errno == ERANGE || errno == EINVAL) {
		_error->Errno("rred", "startline is an invalid number");
		return ED_PARSER;
	}
	if (startline > line) {
		_error->Error("rred: The start line (%lu) of the next command is higher than the last line (%lu). This is not allowed.", startline, line);
		return ED_ORDERING;
	}
	unsigned long stopline;
	if (*idx == ',') {
		idx++;
		errno=0;
		stopline = strtol(idx, &idx, 10);
		if (errno == ERANGE || errno == EINVAL) {
			_error->Errno("rred", "stopline is an invalid number");
			return ED_PARSER;
		}
	}
	else {
		stopline = startline;
	}
	line = startline;

	// which command to execute on this line(s)?
	switch (*idx) {
		case MODE_CHANGED:
			if (Debug == true)
				std::clog << "Change from line " << startline << " to " << stopline << std::endl;
			break;
		case MODE_ADDED:
			if (Debug == true)
				std::clog << "Insert after line " << startline << std::endl;
			break;
		case MODE_DELETED:
			if (Debug == true)
				std::clog << "Delete from line " << startline << " to " << stopline << std::endl;
			break;
		default:
			_error->Error("rred: Unknown ed command '%c'. Abort.", *idx);
			return ED_PARSER;
	}
	unsigned char mode = *idx;

	// save the current position
	unsigned const long pos = ftell(ed_cmds);

	// if this is add or change then go to the next full stop
	unsigned int data_length = 0;
	if (mode == MODE_CHANGED || mode == MODE_ADDED) {
		do {
			ignoreLineInFile(ed_cmds, buffer);
			data_length++;
		}
		while (strncmp(buffer, ".", 1) != 0);
		data_length--; // the dot should not be copied
	}

	// do the recursive call - the last command is the one we need to execute at first
	const State child = applyFile(ed_cmds, in_file, out_file, line, buffer, hash);
	if (child != ED_OK) {
		return child;
	}

	// change and delete are working on "line" - add is done after "line"
	if (mode != MODE_ADDED)
		line++;

	// first wind to the current position and copy over all unchanged lines
	if (line < startline) {
		copyLinesFromFileToFile(in_file, out_file, (startline - line), hash, buffer);
		line = startline;
	}

	if (mode != MODE_ADDED)
		line--;

	// include data from ed script
	if (mode == MODE_CHANGED || mode == MODE_ADDED) {
		fseek(ed_cmds, pos, SEEK_SET);
		copyLinesFromFileToFile(ed_cmds, out_file, data_length, hash, buffer);
	}

	// ignore the corresponding number of lines from input
	if (mode == MODE_CHANGED || mode == MODE_DELETED) {
		while (line < stopline) {
			ignoreLineInFile(in_file, buffer);
			line++;
		}
	}
	return ED_OK;
}
										/*}}}*/
void RredMethod::copyLinesFromFileToFile(FILE *fin, FILE *fout, unsigned int lines,/*{{{*/
					Hashes *hash, char *buffer) const {
	while (0 < lines--) {
		do {
			fgets(buffer, BUF_SIZE, fin);
			size_t const written = fwrite(buffer, 1, strlen(buffer), fout);
			hash->Add((unsigned char*)buffer, written);
		} while (strlen(buffer) == (BUF_SIZE - 1) &&
		       buffer[BUF_SIZE - 2] != '\n');
	}
}
										/*}}}*/
void RredMethod::ignoreLineInFile(FILE *fin, char *buffer) const {		/*{{{*/
	fgets(buffer, BUF_SIZE, fin);
	while (strlen(buffer) == (BUF_SIZE - 1) &&
	       buffer[BUF_SIZE - 2] != '\n') {
		fgets(buffer, BUF_SIZE, fin);
		buffer[0] = ' ';
	}
}
										/*}}}*/
RredMethod::State RredMethod::patchFile(FileFd &Patch, FileFd &From,		/*{{{*/
					FileFd &out_file, Hashes *hash) const {
   char buffer[BUF_SIZE];
   FILE* fFrom = fdopen(From.Fd(), "r");
   FILE* fPatch = fdopen(Patch.Fd(), "r");
   FILE* fTo = fdopen(out_file.Fd(), "w");

   /* we do a tail recursion to read the commands in the right order */
   unsigned long line = -1; // assign highest possible value
   State const result = applyFile(fPatch, fFrom, fTo, line, buffer, hash);
   
   /* read the rest from infile */
   if (result == ED_OK) {
      while (fgets(buffer, BUF_SIZE, fFrom) != NULL) {
         size_t const written = fwrite(buffer, 1, strlen(buffer), fTo);
         hash->Add((unsigned char*)buffer, written);
      }
      fflush(fTo);
   }
   return result;
}
										/*}}}*/
struct EdCommand {								/*{{{*/
  size_t data_start;
  size_t data_end;
  size_t data_lines;
  size_t first_line;
  size_t last_line;
  char type;
};
#define IOV_COUNT 1024 /* Don't really want IOV_MAX since it can be arbitrarily large */
										/*}}}*/
RredMethod::State RredMethod::patchMMap(FileFd &Patch, FileFd &From,		/*{{{*/
					FileFd &out_file, Hashes *hash) const {
#ifdef _POSIX_MAPPED_FILES
	MMap ed_cmds(Patch, MMap::ReadOnly);
	MMap in_file(From, MMap::ReadOnly);

	if (ed_cmds.Size() == 0 || in_file.Size() == 0)
		return MMAP_FAILED;

	EdCommand* commands = 0;
	size_t command_count = 0;
	size_t command_alloc = 0;

	const char* begin = (char*) ed_cmds.Data();
	const char* end = begin;
	const char* ed_end = (char*) ed_cmds.Data() + ed_cmds.Size();

	const char* input = (char*) in_file.Data();
	const char* input_end = (char*) in_file.Data() + in_file.Size();

	size_t i;

	/* 1. Parse entire script.  It is executed in reverse order, so we cather it
	 *    in the `commands' buffer first
	 */

	for(;;) {
		EdCommand cmd;
		cmd.data_start = 0;
		cmd.data_end = 0;

		while(begin != ed_end && *begin == '\n')
			++begin;
		while(end != ed_end && *end != '\n')
			++end;
		if(end == ed_end && begin == end)
			break;

		/* Determine command range */
		const char* tmp = begin;

		for(;;) {
			/* atoll is safe despite lacking NUL-termination; we know there's an
			 * alphabetic character at end[-1]
			 */
			if(tmp == end) {
				cmd.first_line = atol(begin);
				cmd.last_line = cmd.first_line;
				break;
			}
			if(*tmp == ',') {
				cmd.first_line = atol(begin);
				cmd.last_line = atol(tmp + 1);
				break;
			}
			++tmp;
		}

		// which command to execute on this line(s)?
		switch (end[-1]) {
			case MODE_CHANGED:
				if (Debug == true)
					std::clog << "Change from line " << cmd.first_line << " to " << cmd.last_line << std::endl;
				break;
			case MODE_ADDED:
				if (Debug == true)
					std::clog << "Insert after line " << cmd.first_line << std::endl;
				break;
			case MODE_DELETED:
				if (Debug == true)
					std::clog << "Delete from line " << cmd.first_line << " to " << cmd.last_line << std::endl;
				break;
			default:
				_error->Error("rred: Unknown ed command '%c'. Abort.", end[-1]);
				free(commands);
				return ED_PARSER;
		}
		cmd.type = end[-1];

		/* Determine the size of the inserted text, so we don't have to scan this
		 * text again later.
		 */
		begin = end + 1;
		end = begin;
		cmd.data_lines = 0;

		if(cmd.type == MODE_ADDED || cmd.type == MODE_CHANGED) {
			cmd.data_start = begin - (char*) ed_cmds.Data();
			while(end != ed_end) {
				if(*end == '\n') {
					if(end[-1] == '.' && end[-2] == '\n')
						break;
					++cmd.data_lines;
				}
				++end;
			}
			cmd.data_end = end - (char*) ed_cmds.Data() - 1;
			begin = end + 1;
			end = begin;
		}
		if(command_count == command_alloc) {
			command_alloc = (command_alloc + 64) * 3 / 2;
			commands = (EdCommand*) realloc(commands, command_alloc * sizeof(EdCommand));
		}
		commands[command_count++] = cmd;
	}

	struct iovec* iov = new struct iovec[IOV_COUNT];
	size_t iov_size = 0;

	size_t amount, remaining;
	size_t line = 1;
	EdCommand* cmd;

	/* 2. Execute script.  We gather writes in a `struct iov' array, and flush
	 *    using writev to minimize the number of system calls.  Data is read
	 *    directly from the memory mappings of the input file and the script.
	 */

	for(i = command_count; i-- > 0; ) {
		cmd = &commands[i];
		if(cmd->type == MODE_ADDED)
			amount = cmd->first_line + 1;
		else
			amount = cmd->first_line;

		if(line < amount) {
			begin = input;
			while(line != amount) {
				input = (const char*) memchr(input, '\n', input_end - input);
				if(!input)
					break;
				++line;
				++input;
			}

			iov[iov_size].iov_base = (void*) begin;
			iov[iov_size].iov_len = input - begin;
			hash->Add((const unsigned char*) begin, input - begin);

			if(++iov_size == IOV_COUNT) {
				writev(out_file.Fd(), iov, IOV_COUNT);
				iov_size = 0;
			}
		}

		if(cmd->type == MODE_DELETED || cmd->type == MODE_CHANGED) {
			remaining = (cmd->last_line - cmd->first_line) + 1;
			line += remaining;
			while(remaining) {
				input = (const char*) memchr(input, '\n', input_end - input);
				if(!input)
					break;
				--remaining;
				++input;
			}
		}

		if(cmd->type == MODE_CHANGED || cmd->type == MODE_ADDED) {
			if(cmd->data_end != cmd->data_start) {
				iov[iov_size].iov_base = (void*) ((char*)ed_cmds.Data() + cmd->data_start);
				iov[iov_size].iov_len = cmd->data_end - cmd->data_start;
				hash->Add((const unsigned char*) ((char*)ed_cmds.Data() + cmd->data_start),
				iov[iov_size].iov_len);

				if(++iov_size == IOV_COUNT) {
					writev(out_file.Fd(), iov, IOV_COUNT);
					iov_size = 0;
				}
			}
		}
	}

	if(input != input_end) {
		iov[iov_size].iov_base = (void*) input;
		iov[iov_size].iov_len = input_end - input;
		hash->Add((const unsigned char*) input, input_end - input);
		++iov_size;
	}

	if(iov_size) {
		writev(out_file.Fd(), iov, iov_size);
		iov_size = 0;
	}

	for(i = 0; i < iov_size; i += IOV_COUNT) {
		if(iov_size - i < IOV_COUNT)
			writev(out_file.Fd(), iov + i, iov_size - i);
		else
			writev(out_file.Fd(), iov + i, IOV_COUNT);
	}

	delete [] iov;
	free(commands);

	return ED_OK;
#else
	return MMAP_FAILED;
#endif
}
										/*}}}*/
bool RredMethod::Fetch(FetchItem *Itm)						/*{{{*/
{
   Debug = _config->FindB("Debug::pkgAcquire::RRed", false);
   URI Get = Itm->Uri;
   string Path = Get.Host + Get.Path; // To account for relative paths

   FetchResult Res;
   Res.Filename = Itm->DestFile;
   if (Itm->Uri.empty() == true) {
      Path = Itm->DestFile;
      Itm->DestFile.append(".result");
   } else
      URIStart(Res);

   if (Debug == true) 
      std::clog << "Patching " << Path << " with " << Path 
         << ".ed and putting result into " << Itm->DestFile << std::endl;
   // Open the source and destination files (the d'tor of FileFd will do 
   // the cleanup/closing of the fds)
   FileFd From(Path,FileFd::ReadOnly);
   FileFd Patch(Path+".ed",FileFd::ReadOnly);
   FileFd To(Itm->DestFile,FileFd::WriteAtomic);   
   To.EraseOnFailure();
   if (_error->PendingError() == true)
      return false;
   
   Hashes Hash;
   // now do the actual patching
   State const result = patchMMap(Patch, From, To, &Hash);
   if (result == MMAP_FAILED) {
      // retry with patchFile
      lseek(Patch.Fd(), 0, SEEK_SET);
      lseek(From.Fd(), 0, SEEK_SET);
      To.Open(Itm->DestFile,FileFd::WriteAtomic);
      if (_error->PendingError() == true)
         return false;
      if (patchFile(Patch, From, To, &Hash) != ED_OK) {
	 return _error->WarningE("rred", _("Could not patch %s with mmap and with file operation usage - the patch seems to be corrupt."), Path.c_str());
      } else if (Debug == true) {
	 std::clog << "rred: finished file patching of " << Path  << " after mmap failed." << std::endl;
      }
   } else if (result != ED_OK) {
      return _error->Errno("rred", _("Could not patch %s with mmap (but no mmap specific fail) - the patch seems to be corrupt."), Path.c_str());
   } else if (Debug == true) {
      std::clog << "rred: finished mmap patching of " << Path << std::endl;
   }

   // write out the result
   From.Close();
   Patch.Close();
   To.Close();

   /* Transfer the modification times from the patch file
      to be able to see in which state the file should be
      and use the access time from the "old" file */
   struct stat BufBase, BufPatch;
   if (stat(Path.c_str(),&BufBase) != 0 ||
       stat(string(Path+".ed").c_str(),&BufPatch) != 0)
      return _error->Errno("stat",_("Failed to stat"));

   struct utimbuf TimeBuf;
   TimeBuf.actime = BufBase.st_atime;
   TimeBuf.modtime = BufPatch.st_mtime;
   if (utime(Itm->DestFile.c_str(),&TimeBuf) != 0)
      return _error->Errno("utime",_("Failed to set modification time"));

   if (stat(Itm->DestFile.c_str(),&BufBase) != 0)
      return _error->Errno("stat",_("Failed to stat"));

   // return done
   Res.LastModified = BufBase.st_mtime;
   Res.Size = BufBase.st_size;
   Res.TakeHashes(Hash);
   URIDone(Res);

   return true;
}
										/*}}}*/
/** \brief Wrapper class for testing rred */					/*{{{*/
class TestRredMethod : public RredMethod {
public:
	/** \brief Run rred in debug test mode
	 *
	 *  This method can be used to run the rred method outside
	 *  of the "normal" acquire environment for easier testing.
	 *
	 *  \param base basename of all files involved in this rred test
	 */
	bool Run(char const *base) {
		_config->CndSet("Debug::pkgAcquire::RRed", "true");
		FetchItem *test = new FetchItem;
		test->DestFile = base;
		return Fetch(test);
	}
};
										/*}}}*/
/** \brief Starter for the rred method (or its test method)			{{{
 *
 *  Used without parameters is the normal behavior for methods for
 *  the APT acquire system. While this works great for the acquire system
 *  it is very hard to test the method and therefore the method also
 *  accepts one parameter which will switch it directly to debug test mode:
 *  The test mode expects that if "Testfile" is given as parameter
 *  the file "Testfile" should be ed-style patched with "Testfile.ed"
 *  and will write the result to "Testfile.result".
 */
int main(int argc, char *argv[]) {
	if (argc <= 1) {
		RredMethod Mth;
		return Mth.Run();
	} else {
		TestRredMethod Mth;
		bool result = Mth.Run(argv[1]);
		_error->DumpErrors();
		return result;
	}
}
										/*}}}*/
Commit	Line	Data
bb1293d9	1	// Includes /{{{/
2e178d1c	2	#include <apt-pkg/fileutl.h>
bb1293d9	3	#include <apt-pkg/mmap.h>
2e178d1c MV	4	#include <apt-pkg/error.h>
	5	#include <apt-pkg/acquire-method.h>
	6	#include <apt-pkg/strutl.h>
	7	#include <apt-pkg/hashes.h>
	8
	9	#include <sys/stat.h>
bb1293d9	10	#include <sys/uio.h>
2e178d1c MV	11	#include <unistd.h>
	12	#include <utime.h>
	13	#include <stdio.h>
	14	#include <errno.h>
	15	#include <apti18n.h>
bb1293d9 DK	16	/}}}/
	17	/** \brief RredMethod - ed-style incremential patch method {{{
	18	*
	19	* This method implements a patch functionality similar to "patch --ed" that is
	20	* used by the "tiffany" incremental packages download stuff. It differs from
	21	* "ed" insofar that it is way more restricted (and therefore secure).
	22	* The currently supported ed commands are "<em>c</em>hange", "<em>a</em>dd" and
	23	* "<em>d</em>elete" (diff doesn't output any other).
	24	* Additionally the records must be reverse sorted by line number and
	25	* may not overlap (diff seems to produce this kind of output).
d84cd865	26	* */
bb1293d9 DK	27	class RredMethod : public pkgAcqMethod {
	28	bool Debug;
	29	// the size of this doesn't really matter (except for performance)
	30	const static int BUF_SIZE = 1024;
	31	// the supported ed commands
	32	enum Mode {MODE_CHANGED='c', MODE_DELETED='d', MODE_ADDED='a'};
	33	// return values
	34	enum State {ED_OK, ED_ORDERING, ED_PARSER, ED_FAILURE, MMAP_FAILED};
d84cd865	35
bb1293d9 DK	36	State applyFile(FILE ed_cmds, FILE in_file, FILE *out_file,
	37	unsigned long &line, char buffer, Hashes hash) const;
	38	void ignoreLineInFile(FILE fin, char buffer) const;
	39	void copyLinesFromFileToFile(FILE fin, FILE fout, unsigned int lines,
	40	Hashes hash, char buffer) const;
2e178d1c	41
bb1293d9 DK	42	State patchFile(FileFd &Patch, FileFd &From, FileFd &out_file, Hashes *hash) const;
	43	State patchMMap(FileFd &Patch, FileFd &From, FileFd &out_file, Hashes *hash) const;
	44
	45	protected:
	46	// the methods main method
	47	virtual bool Fetch(FetchItem *Itm);
	48
	49	public:
	50	RredMethod() : pkgAcqMethod("1.1",SingleInstance \| SendConfig) {};
2e178d1c	51	};
bb1293d9 DK	52	/}}}/
	53	/** \brief applyFile - in reverse order with a tail recursion {{{
	54	*
	55	* As it is expected that the commands are in reversed order in the patch file
	56	* we check in the first half if the command is valid, but doesn't execute it
	57	* and move a step deeper. After reaching the end of the file we apply the
	58	* patches in the correct order: last found command first.
	59	*
	60	* \param ed_cmds patch file to apply
	61	* \param in_file base file we want to patch
	62	* \param out_file file to write the patched result to
	63	* \param line of command operation
	64	* \param buffer internal used read/write buffer
	65	* \param hash the created file for correctness
	66	* \return the success State of the ed command executor
	67	*/
	68	RredMethod::State RredMethod::applyFile(FILE ed_cmds, FILE in_file, FILE *out_file,
	69	unsigned long &line, char buffer, Hashes hash) const {
	70	// get the current command and parse it
	71	if (fgets(buffer, BUF_SIZE, ed_cmds) == NULL) {
	72	if (Debug == true)
	73	std::clog << "rred: encounter end of file - we can start patching now." << std::endl;
	74	line = 0;
	75	return ED_OK;
	76	}
2e178d1c	77
bb1293d9 DK	78	// parse in the effected linenumbers
	79	char* idx;
	80	errno=0;
	81	unsigned long const startline = strtol(buffer, &idx, 10);
	82	if (errno == ERANGE \|\| errno == EINVAL) {
	83	_error->Errno("rred", "startline is an invalid number");
	84	return ED_PARSER;
	85	}
	86	if (startline > line) {
	87	_error->Error("rred: The start line (%lu) of the next command is higher than the last line (%lu). This is not allowed.", startline, line);
	88	return ED_ORDERING;
	89	}
	90	unsigned long stopline;
	91	if (*idx == ',') {
	92	idx++;
	93	errno=0;
	94	stopline = strtol(idx, &idx, 10);
	95	if (errno == ERANGE \|\| errno == EINVAL) {
	96	_error->Errno("rred", "stopline is an invalid number");
	97	return ED_PARSER;
	98	}
	99	}
	100	else {
	101	stopline = startline;
	102	}
	103	line = startline;
	104
	105	// which command to execute on this line(s)?
	106	switch (*idx) {
	107	case MODE_CHANGED:
	108	if (Debug == true)
	109	std::clog << "Change from line " << startline << " to " << stopline << std::endl;
	110	break;
	111	case MODE_ADDED:
	112	if (Debug == true)
	113	std::clog << "Insert after line " << startline << std::endl;
	114	break;
	115	case MODE_DELETED:
	116	if (Debug == true)
	117	std::clog << "Delete from line " << startline << " to " << stopline << std::endl;
	118	break;
	119	default:
	120	_error->Error("rred: Unknown ed command '%c'. Abort.", *idx);
	121	return ED_PARSER;
	122	}
	123	unsigned char mode = *idx;
	124
	125	// save the current position
	126	unsigned const long pos = ftell(ed_cmds);
	127
	128	// if this is add or change then go to the next full stop
	129	unsigned int data_length = 0;
	130	if (mode == MODE_CHANGED \|\| mode == MODE_ADDED) {
	131	do {
	132	ignoreLineInFile(ed_cmds, buffer);
	133	data_length++;
	134	}
	135	while (strncmp(buffer, ".", 1) != 0);
	136	data_length--; // the dot should not be copied
	137	}
	138
	139	// do the recursive call - the last command is the one we need to execute at first
	140	const State child = applyFile(ed_cmds, in_file, out_file, line, buffer, hash);
	141	if (child != ED_OK) {
142	return child;
143	}
144
145	// change and delete are working on "line" - add is done after "line"
146	if (mode != MODE_ADDED)
147	line++;
148
149	// first wind to the current position and copy over all unchanged lines
150	if (line < startline) {
151	copyLinesFromFileToFile(in_file, out_file, (startline - line), hash, buffer);
152	line = startline;
153	}
2e178d1c	154
bb1293d9 DK	155	if (mode != MODE_ADDED)
	156	line--;
	157
	158	// include data from ed script
	159	if (mode == MODE_CHANGED \|\| mode == MODE_ADDED) {
	160	fseek(ed_cmds, pos, SEEK_SET);
	161	copyLinesFromFileToFile(ed_cmds, out_file, data_length, hash, buffer);
	162	}
	163
	164	// ignore the corresponding number of lines from input
	165	if (mode == MODE_CHANGED \|\| mode == MODE_DELETED) {
	166	while (line < stopline) {
	167	ignoreLineInFile(in_file, buffer);
	168	line++;
	169	}
	170	}
	171	return ED_OK;
	172	}
	173	/}}}/
	174	void RredMethod::copyLinesFromFileToFile(FILE fin, FILE fout, unsigned int lines,/{{{/
	175	Hashes hash, char buffer) const {
	176	while (0 < lines--) {
	177	do {
	178	fgets(buffer, BUF_SIZE, fin);
	179	size_t const written = fwrite(buffer, 1, strlen(buffer), fout);
	180	hash->Add((unsigned char*)buffer, written);
	181	} while (strlen(buffer) == (BUF_SIZE - 1) &&
	182	buffer[BUF_SIZE - 2] != '\n');
	183	}
	184	}
	185	/}}}/
	186	void RredMethod::ignoreLineInFile(FILE fin, char buffer) const { /{{{/
	187	fgets(buffer, BUF_SIZE, fin);
	188	while (strlen(buffer) == (BUF_SIZE - 1) &&
	189	buffer[BUF_SIZE - 2] != '\n') {
	190	fgets(buffer, BUF_SIZE, fin);
	191	buffer[0] = ' ';
	192	}
	193	}
	194	/}}}/
	195	RredMethod::State RredMethod::patchFile(FileFd &Patch, FileFd &From, /{{{/
	196	FileFd &out_file, Hashes *hash) const {
d84cd865	197	char buffer[BUF_SIZE];
bb1293d9 DK	198	FILE* fFrom = fdopen(From.Fd(), "r");
	199	FILE* fPatch = fdopen(Patch.Fd(), "r");
	200	FILE* fTo = fdopen(out_file.Fd(), "w");
	201
d84cd865	202	/* we do a tail recursion to read the commands in the right order */
bb1293d9 DK	203	unsigned long line = -1; // assign highest possible value
bb1293d9 DK	204	State const result = applyFile(fPatch, fFrom, fTo, line, buffer, hash);
d84cd865 MV	205
d84cd865 MV	206	/* read the rest from infile */
bb1293d9 DK	207	if (result == ED_OK) {
	208	while (fgets(buffer, BUF_SIZE, fFrom) != NULL) {
	209	size_t const written = fwrite(buffer, 1, strlen(buffer), fTo);
d84cd865 MV	210	hash->Add((unsigned char*)buffer, written);
d84cd865 MV	211	}
bb1293d9	212	fflush(fTo);
d84cd865	213	}
bb1293d9	214	return result;
2e178d1c	215	}
bb1293d9 DK	216	/}}}/
	217	struct EdCommand { /{{{/
	218	size_t data_start;
	219	size_t data_end;
	220	size_t data_lines;
	221	size_t first_line;
	222	size_t last_line;
	223	char type;
	224	};
	225	#define IOV_COUNT 1024 /* Don't really want IOV_MAX since it can be arbitrarily large */
	226	/}}}/
	227	RredMethod::State RredMethod::patchMMap(FileFd &Patch, FileFd &From, /{{{/
	228	FileFd &out_file, Hashes *hash) const {
	229	#ifdef _POSIX_MAPPED_FILES
	230	MMap ed_cmds(Patch, MMap::ReadOnly);
	231	MMap in_file(From, MMap::ReadOnly);
	232
	233	if (ed_cmds.Size() == 0 \|\| in_file.Size() == 0)
	234	return MMAP_FAILED;
	235
	236	EdCommand* commands = 0;
	237	size_t command_count = 0;
	238	size_t command_alloc = 0;
	239
	240	const char* begin = (char*) ed_cmds.Data();
	241	const char* end = begin;
	242	const char* ed_end = (char*) ed_cmds.Data() + ed_cmds.Size();
	243
	244	const char* input = (char*) in_file.Data();
	245	const char* input_end = (char*) in_file.Data() + in_file.Size();
	246
	247	size_t i;
	248
	249	/* 1. Parse entire script. It is executed in reverse order, so we cather it
	250	* in the `commands' buffer first
	251	*/
	252
	253	for(;;) {
	254	EdCommand cmd;
	255	cmd.data_start = 0;
	256	cmd.data_end = 0;
	257
	258	while(begin != ed_end && *begin == '\n')
	259	++begin;
	260	while(end != ed_end && *end != '\n')
	261	++end;
	262	if(end == ed_end && begin == end)
	263	break;
	264
	265	/* Determine command range */
	266	const char* tmp = begin;
	267
	268	for(;;) {
	269	/* atoll is safe despite lacking NUL-termination; we know there's an
	270	* alphabetic character at end[-1]
	271	*/
	272	if(tmp == end) {
	273	cmd.first_line = atol(begin);
	274	cmd.last_line = cmd.first_line;
	275	break;
	276	}
	277	if(*tmp == ',') {
	278	cmd.first_line = atol(begin);
	279	cmd.last_line = atol(tmp + 1);
280	break;
281	}
282	++tmp;
283	}
284
285	// which command to execute on this line(s)?
286	switch (end[-1]) {
287	case MODE_CHANGED:
288	if (Debug == true)
289	std::clog << "Change from line " << cmd.first_line << " to " << cmd.last_line << std::endl;
290	break;
291	case MODE_ADDED:
292	if (Debug == true)
293	std::clog << "Insert after line " << cmd.first_line << std::endl;
294	break;
295	case MODE_DELETED:
296	if (Debug == true)
297	std::clog << "Delete from line " << cmd.first_line << " to " << cmd.last_line << std::endl;
298	break;
299	default:
300	_error->Error("rred: Unknown ed command '%c'. Abort.", end[-1]);
301	free(commands);
302	return ED_PARSER;
303	}
304	cmd.type = end[-1];
305
306	/* Determine the size of the inserted text, so we don't have to scan this
307	* text again later.
308	*/
309	begin = end + 1;
310	end = begin;
311	cmd.data_lines = 0;
312
313	if(cmd.type == MODE_ADDED \|\| cmd.type == MODE_CHANGED) {
314	cmd.data_start = begin - (char*) ed_cmds.Data();
315	while(end != ed_end) {
316	if(*end == '\n') {
317	if(end[-1] == '.' && end[-2] == '\n')
318	break;
319	++cmd.data_lines;
320	}
321	++end;
322	}
323	cmd.data_end = end - (char*) ed_cmds.Data() - 1;
324	begin = end + 1;
325	end = begin;
326	}
327	if(command_count == command_alloc) {
328	command_alloc = (command_alloc + 64) * 3 / 2;
329	commands = (EdCommand) realloc(commands, command_alloc sizeof(EdCommand));
330	}
331	commands[command_count++] = cmd;
332	}
333
334	struct iovec* iov = new struct iovec[IOV_COUNT];
335	size_t iov_size = 0;
336
337	size_t amount, remaining;
338	size_t line = 1;
339	EdCommand* cmd;
340
341	/* 2. Execute script. We gather writes in a `struct iov' array, and flush
342	* using writev to minimize the number of system calls. Data is read
343	* directly from the memory mappings of the input file and the script.
344	*/
345
346	for(i = command_count; i-- > 0; ) {
347	cmd = &commands[i];
348	if(cmd->type == MODE_ADDED)
349	amount = cmd->first_line + 1;
350	else
351	amount = cmd->first_line;
352
353	if(line < amount) {
354	begin = input;
355	while(line != amount) {
356	input = (const char*) memchr(input, '\n', input_end - input);
357	if(!input)
358	break;
359	++line;
360	++input;
361	}
2e178d1c	362
bb1293d9 DK	363	iov[iov_size].iov_base = (void*) begin;
	364	iov[iov_size].iov_len = input - begin;
	365	hash->Add((const unsigned char*) begin, input - begin);
2e178d1c	366
bb1293d9 DK	367	if(++iov_size == IOV_COUNT) {
	368	writev(out_file.Fd(), iov, IOV_COUNT);
	369	iov_size = 0;
	370	}
	371	}
	372
	373	if(cmd->type == MODE_DELETED \|\| cmd->type == MODE_CHANGED) {
	374	remaining = (cmd->last_line - cmd->first_line) + 1;
	375	line += remaining;
	376	while(remaining) {
	377	input = (const char*) memchr(input, '\n', input_end - input);
	378	if(!input)
	379	break;
	380	--remaining;
	381	++input;
	382	}
	383	}
	384
	385	if(cmd->type == MODE_CHANGED \|\| cmd->type == MODE_ADDED) {
	386	if(cmd->data_end != cmd->data_start) {
	387	iov[iov_size].iov_base = (void) ((char)ed_cmds.Data() + cmd->data_start);
	388	iov[iov_size].iov_len = cmd->data_end - cmd->data_start;
	389	hash->Add((const unsigned char) ((char)ed_cmds.Data() + cmd->data_start),
	390	iov[iov_size].iov_len);
	391
	392	if(++iov_size == IOV_COUNT) {
	393	writev(out_file.Fd(), iov, IOV_COUNT);
	394	iov_size = 0;
	395	}
	396	}
	397	}
	398	}
	399
	400	if(input != input_end) {
	401	iov[iov_size].iov_base = (void*) input;
	402	iov[iov_size].iov_len = input_end - input;
	403	hash->Add((const unsigned char*) input, input_end - input);
	404	++iov_size;
	405	}
	406
	407	if(iov_size) {
	408	writev(out_file.Fd(), iov, iov_size);
	409	iov_size = 0;
	410	}
	411
	412	for(i = 0; i < iov_size; i += IOV_COUNT) {
	413	if(iov_size - i < IOV_COUNT)
	414	writev(out_file.Fd(), iov + i, iov_size - i);
	415	else
	416	writev(out_file.Fd(), iov + i, IOV_COUNT);
	417	}
	418
	419	delete [] iov;
	420	free(commands);
	421
	422	return ED_OK;
	423	#else
	424	return MMAP_FAILED;
	425	#endif
	426	}
	427	/}}}/
	428	bool RredMethod::Fetch(FetchItem Itm) /{{{*/
2e178d1c	429	{
bb1293d9	430	Debug = _config->FindB("Debug::pkgAcquire::RRed", false);
2e178d1c MV	431	URI Get = Itm->Uri;
2e178d1c MV	432	string Path = Get.Host + Get.Path; // To account for relative paths
bb1293d9	433
2e178d1c MV	434	FetchResult Res;
2e178d1c MV	435	Res.Filename = Itm->DestFile;
bb1293d9 DK	436	if (Itm->Uri.empty() == true) {
	437	Path = Itm->DestFile;
	438	Itm->DestFile.append(".result");
	439	} else
	440	URIStart(Res);
4a0a786f	441
6040f589 MV	442	if (Debug == true)
	443	std::clog << "Patching " << Path << " with " << Path
	444	<< ".ed and putting result into " << Itm->DestFile << std::endl;
59a704f0 MV	445	// Open the source and destination files (the d'tor of FileFd will do
59a704f0 MV	446	// the cleanup/closing of the fds)
2e178d1c MV	447	FileFd From(Path,FileFd::ReadOnly);
2e178d1c MV	448	FileFd Patch(Path+".ed",FileFd::ReadOnly);
22041bd2	449	FileFd To(Itm->DestFile,FileFd::WriteAtomic);
2e178d1c MV	450	To.EraseOnFailure();
	451	if (_error->PendingError() == true)
	452	return false;
	453
	454	Hashes Hash;
2e178d1c	455	// now do the actual patching
bb1293d9 DK	456	State const result = patchMMap(Patch, From, To, &Hash);
	457	if (result == MMAP_FAILED) {
	458	// retry with patchFile
	459	lseek(Patch.Fd(), 0, SEEK_SET);
	460	lseek(From.Fd(), 0, SEEK_SET);
22041bd2	461	To.Open(Itm->DestFile,FileFd::WriteAtomic);
bb1293d9 DK	462	if (_error->PendingError() == true)
	463	return false;
	464	if (patchFile(Patch, From, To, &Hash) != ED_OK) {
	465	return _error->WarningE("rred", _("Could not patch %s with mmap and with file operation usage - the patch seems to be corrupt."), Path.c_str());
	466	} else if (Debug == true) {
	467	std::clog << "rred: finished file patching of " << Path << " after mmap failed." << std::endl;
	468	}
	469	} else if (result != ED_OK) {
	470	return _error->Errno("rred", _("Could not patch %s with mmap (but no mmap specific fail) - the patch seems to be corrupt."), Path.c_str());
	471	} else if (Debug == true) {
	472	std::clog << "rred: finished mmap patching of " << Path << std::endl;
3de9ff77 MV	473	}
	474
	475	// write out the result
3de9ff77 MV	476	From.Close();
	477	Patch.Close();
	478	To.Close();
	479
1082d4c7 DK	480	/* Transfer the modification times from the patch file
	481	to be able to see in which state the file should be
	482	and use the access time from the "old" file */
	483	struct stat BufBase, BufPatch;
	484	if (stat(Path.c_str(),&BufBase) != 0 \|\|
	485	stat(string(Path+".ed").c_str(),&BufPatch) != 0)
3de9ff77 MV	486	return _error->Errno("stat",_("Failed to stat"));
	487
	488	struct utimbuf TimeBuf;
1082d4c7 DK	489	TimeBuf.actime = BufBase.st_atime;
1082d4c7 DK	490	TimeBuf.modtime = BufPatch.st_mtime;
3de9ff77 MV	491	if (utime(Itm->DestFile.c_str(),&TimeBuf) != 0)
	492	return _error->Errno("utime",_("Failed to set modification time"));
	493
1082d4c7	494	if (stat(Itm->DestFile.c_str(),&BufBase) != 0)
3de9ff77 MV	495	return _error->Errno("stat",_("Failed to stat"));
	496
	497	// return done
1082d4c7 DK	498	Res.LastModified = BufBase.st_mtime;
1082d4c7 DK	499	Res.Size = BufBase.st_size;
2e178d1c MV	500	Res.TakeHashes(Hash);
2e178d1c MV	501	URIDone(Res);
3de9ff77	502
2e178d1c MV	503	return true;
2e178d1c MV	504	}
bb1293d9 DK	505	/}}}/
	506	/** \brief Wrapper class for testing rred / /{{{*/
	507	class TestRredMethod : public RredMethod {
	508	public:
	509	/** \brief Run rred in debug test mode
	510	*
	511	* This method can be used to run the rred method outside
	512	* of the "normal" acquire environment for easier testing.
	513	*
	514	* \param base basename of all files involved in this rred test
	515	*/
	516	bool Run(char const *base) {
	517	_config->CndSet("Debug::pkgAcquire::RRed", "true");
	518	FetchItem *test = new FetchItem;
	519	test->DestFile = base;
	520	return Fetch(test);
	521	}
	522	};
	523	/}}}/
	524	/** \brief Starter for the rred method (or its test method) {{{
	525	*
	526	* Used without parameters is the normal behavior for methods for
	527	* the APT acquire system. While this works great for the acquire system
	528	* it is very hard to test the method and therefore the method also
	529	* accepts one parameter which will switch it directly to debug test mode:
	530	* The test mode expects that if "Testfile" is given as parameter
	531	* the file "Testfile" should be ed-style patched with "Testfile.ed"
	532	* and will write the result to "Testfile.result".
	533	*/
	534	int main(int argc, char *argv[]) {
	535	if (argc <= 1) {
	536	RredMethod Mth;
	537	return Mth.Run();
	538	} else {
	539	TestRredMethod Mth;
	540	bool result = Mth.Run(argv[1]);
	541	_error->DumpErrors();
	542	return result;
	543	}
2e178d1c	544	}
bb1293d9	545	/}}}/