diff options
Diffstat (limited to 'methods/rred.cc')
-rw-r--r-- | methods/rred.cc | 785 |
1 files changed, 785 insertions, 0 deletions
diff --git a/methods/rred.cc b/methods/rred.cc new file mode 100644 index 000000000..2e5008d46 --- /dev/null +++ b/methods/rred.cc @@ -0,0 +1,785 @@ +// Copyright (c) 2014 Anthony Towns +// +// This program is free software; you can redistribute it and/or modify +// it under the terms of the GNU General Public License as published by +// the Free Software Foundation; either version 2 of the License, or +// (at your option) any later version. + +#include <config.h> + +#include <apt-pkg/init.h> +#include <apt-pkg/fileutl.h> +#include <apt-pkg/error.h> +#include <apt-pkg/strutl.h> +#include <apt-pkg/hashes.h> +#include <apt-pkg/configuration.h> +#include "aptmethod.h" + +#include <stddef.h> +#include <iostream> +#include <string> +#include <list> +#include <vector> + +#include <assert.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/time.h> + +#include <apti18n.h> + +#define BLOCK_SIZE (512*1024) + +class MemBlock { + char *start; + size_t size; + char *free; + MemBlock *next; + + explicit MemBlock(size_t size) : size(size), next(NULL) + { + free = start = new char[size]; + } + + size_t avail(void) { return size - (free - start); } + + public: + + MemBlock(void) { + free = start = new char[BLOCK_SIZE]; + size = BLOCK_SIZE; + next = NULL; + } + + ~MemBlock() { + delete [] start; + delete next; + } + + void clear(void) { + free = start; + if (next) + next->clear(); + } + + char *add_easy(char *src, size_t len, char *last) + { + if (last) { + for (MemBlock *k = this; k; k = k->next) { + if (k->free == last) { + if (len <= k->avail()) { + char *n = k->add(src, len); + assert(last == n); + if (last == n) + return NULL; + return n; + } else { + break; + } + } else if (last >= start && last < free) { + break; + } + } + } + return add(src, len); + } + + char *add(char *src, size_t len) { + if (len > avail()) { + if (!next) { + if (len > BLOCK_SIZE) { + next = new MemBlock(len); + } else { + next = new MemBlock; + } + } + return next->add(src, len); + } + char *dst = free; + free += len; + memcpy(dst, src, len); + return dst; + } +}; + +struct Change { + /* Ordering: + * + * 1. write out <offset> lines unchanged + * 2. skip <del_cnt> lines from source + * 3. write out <add_cnt> lines (<add>/<add_len>) + */ + size_t offset; + size_t del_cnt; + size_t add_cnt; /* lines */ + size_t add_len; /* bytes */ + char *add; + + explicit Change(size_t off) + { + offset = off; + del_cnt = add_cnt = add_len = 0; + add = NULL; + } + + /* actually, don't write <lines> lines from <add> */ + void skip_lines(size_t lines) + { + while (lines > 0) { + char *s = (char*) memchr(add, '\n', add_len); + assert(s != NULL); + s++; + add_len -= (s - add); + add_cnt--; + lines--; + if (add_len == 0) { + add = NULL; + assert(add_cnt == 0); + assert(lines == 0); + } else { + add = s; + assert(add_cnt > 0); + } + } + } +}; + +class FileChanges { + std::list<struct Change> changes; + std::list<struct Change>::iterator where; + size_t pos; // line number is as far left of iterator as possible + + bool pos_is_okay(void) const + { +#ifdef POSDEBUG + size_t cpos = 0; + std::list<struct Change>::const_iterator x; + for (x = changes.begin(); x != where; ++x) { + assert(x != changes.end()); + cpos += x->offset + x->add_cnt; + } + return cpos == pos; +#else + return true; +#endif + } + + public: + FileChanges() { + where = changes.end(); + pos = 0; + } + + std::list<struct Change>::iterator begin(void) { return changes.begin(); } + std::list<struct Change>::iterator end(void) { return changes.end(); } + + std::list<struct Change>::reverse_iterator rbegin(void) { return changes.rbegin(); } + std::list<struct Change>::reverse_iterator rend(void) { return changes.rend(); } + + void add_change(Change c) { + assert(pos_is_okay()); + go_to_change_for(c.offset); + assert(pos + where->offset == c.offset); + if (c.del_cnt > 0) + delete_lines(c.del_cnt); + assert(pos + where->offset == c.offset); + if (c.add_len > 0) { + assert(pos_is_okay()); + if (where->add_len > 0) + new_change(); + assert(where->add_len == 0 && where->add_cnt == 0); + + where->add_len = c.add_len; + where->add_cnt = c.add_cnt; + where->add = c.add; + } + assert(pos_is_okay()); + merge(); + assert(pos_is_okay()); + } + + private: + void merge(void) + { + while (where->offset == 0 && where != changes.begin()) { + left(); + } + std::list<struct Change>::iterator next = where; + ++next; + + while (next != changes.end() && next->offset == 0) { + where->del_cnt += next->del_cnt; + next->del_cnt = 0; + if (next->add == NULL) { + next = changes.erase(next); + } else if (where->add == NULL) { + where->add = next->add; + where->add_len = next->add_len; + where->add_cnt = next->add_cnt; + next = changes.erase(next); + } else { + ++next; + } + } + } + + void go_to_change_for(size_t line) + { + while(where != changes.end()) { + if (line < pos) { + left(); + continue; + } + if (pos + where->offset + where->add_cnt <= line) { + right(); + continue; + } + // line is somewhere in this slot + if (line < pos + where->offset) { + break; + } else if (line == pos + where->offset) { + return; + } else { + split(line - pos); + right(); + return; + } + } + /* it goes before this patch */ + insert(line-pos); + } + + void new_change(void) { insert(where->offset); } + + void insert(size_t offset) + { + assert(pos_is_okay()); + assert(where == changes.end() || offset <= where->offset); + if (where != changes.end()) + where->offset -= offset; + changes.insert(where, Change(offset)); + --where; + assert(pos_is_okay()); + } + + void split(size_t offset) + { + assert(pos_is_okay()); + + assert(where->offset < offset); + assert(offset < where->offset + where->add_cnt); + + size_t keep_lines = offset - where->offset; + + Change before(*where); + + where->del_cnt = 0; + where->offset = 0; + where->skip_lines(keep_lines); + + before.add_cnt = keep_lines; + before.add_len -= where->add_len; + + changes.insert(where, before); + --where; + assert(pos_is_okay()); + } + + void delete_lines(size_t cnt) + { + std::list<struct Change>::iterator x = where; + assert(pos_is_okay()); + while (cnt > 0) + { + size_t del; + del = x->add_cnt; + if (del > cnt) + del = cnt; + x->skip_lines(del); + cnt -= del; + + ++x; + if (x == changes.end()) { + del = cnt; + } else { + del = x->offset; + if (del > cnt) + del = cnt; + x->offset -= del; + } + where->del_cnt += del; + cnt -= del; + } + assert(pos_is_okay()); + } + + void left(void) { + assert(pos_is_okay()); + --where; + pos -= where->offset + where->add_cnt; + assert(pos_is_okay()); + } + + void right(void) { + assert(pos_is_okay()); + pos += where->offset + where->add_cnt; + ++where; + assert(pos_is_okay()); + } +}; + +class Patch { + FileChanges filechanges; + MemBlock add_text; + + static bool retry_fwrite(char *b, size_t l, FileFd &f, Hashes * const start_hash, Hashes * const end_hash = nullptr) APT_NONNULL(1) + { + if (f.Write(b, l) == false) + return false; + if (start_hash) + start_hash->Add((unsigned char*)b, l); + if (end_hash) + end_hash->Add((unsigned char*)b, l); + return true; + } + + static void dump_rest(FileFd &o, FileFd &i, + Hashes * const start_hash, Hashes * const end_hash) + { + char buffer[BLOCK_SIZE]; + unsigned long long l = 0; + while (i.Read(buffer, sizeof(buffer), &l)) { + if (l ==0 || !retry_fwrite(buffer, l, o, start_hash, end_hash)) + break; + } + } + + static void dump_lines(FileFd &o, FileFd &i, size_t n, + Hashes * const start_hash, Hashes * const end_hash) + { + char buffer[BLOCK_SIZE]; + while (n > 0) { + if (i.ReadLine(buffer, sizeof(buffer)) == NULL) + buffer[0] = '\0'; + size_t const l = strlen(buffer); + if (l == 0 || buffer[l-1] == '\n') + n--; + retry_fwrite(buffer, l, o, start_hash, end_hash); + } + } + + static void skip_lines(FileFd &i, int n, Hashes * const start_hash) + { + char buffer[BLOCK_SIZE]; + while (n > 0) { + if (i.ReadLine(buffer, sizeof(buffer)) == NULL) + buffer[0] = '\0'; + size_t const l = strlen(buffer); + if (l == 0 || buffer[l-1] == '\n') + n--; + if (start_hash) + start_hash->Add((unsigned char*)buffer, l); + } + } + + static void dump_mem(FileFd &o, char *p, size_t s, Hashes *hash) APT_NONNULL(2) { + retry_fwrite(p, s, o, nullptr, hash); + } + + public: + + bool read_diff(FileFd &f, Hashes * const h) + { + char buffer[BLOCK_SIZE]; + bool cmdwanted = true; + + Change ch(std::numeric_limits<size_t>::max()); + if (f.ReadLine(buffer, sizeof(buffer)) == NULL) + return _error->Error("Reading first line of patchfile %s failed", f.Name().c_str()); + do { + if (h != NULL) + h->Add(buffer); + if (cmdwanted) { + char *m, *c; + size_t s, e; + errno = 0; + s = strtoul(buffer, &m, 10); + if (unlikely(m == buffer || s == std::numeric_limits<unsigned long>::max() || errno != 0)) + return _error->Error("Parsing patchfile %s failed: Expected an effected line start", f.Name().c_str()); + else if (*m == ',') { + ++m; + e = strtol(m, &c, 10); + if (unlikely(m == c || e == std::numeric_limits<unsigned long>::max() || errno != 0)) + return _error->Error("Parsing patchfile %s failed: Expected an effected line end", f.Name().c_str()); + if (unlikely(e < s)) + return _error->Error("Parsing patchfile %s failed: Effected lines end %lu is before start %lu", f.Name().c_str(), e, s); + } else { + e = s; + c = m; + } + if (s > ch.offset) + return _error->Error("Parsing patchfile %s failed: Effected line is after previous effected line", f.Name().c_str()); + switch(*c) { + case 'a': + cmdwanted = false; + ch.add = NULL; + ch.add_cnt = 0; + ch.add_len = 0; + ch.offset = s; + ch.del_cnt = 0; + break; + case 'c': + if (unlikely(s == 0)) + return _error->Error("Parsing patchfile %s failed: Change command can't effect line zero", f.Name().c_str()); + cmdwanted = false; + ch.add = NULL; + ch.add_cnt = 0; + ch.add_len = 0; + ch.offset = s - 1; + ch.del_cnt = e - s + 1; + break; + case 'd': + if (unlikely(s == 0)) + return _error->Error("Parsing patchfile %s failed: Delete command can't effect line zero", f.Name().c_str()); + ch.offset = s - 1; + ch.del_cnt = e - s + 1; + ch.add = NULL; + ch.add_cnt = 0; + ch.add_len = 0; + filechanges.add_change(ch); + break; + default: + return _error->Error("Parsing patchfile %s failed: Unknown command", f.Name().c_str()); + } + } else { /* !cmdwanted */ + if (strcmp(buffer, ".\n") == 0) { + cmdwanted = true; + filechanges.add_change(ch); + } else { + char *last = NULL; + char *add; + size_t l; + if (ch.add) + last = ch.add + ch.add_len; + l = strlen(buffer); + add = add_text.add_easy(buffer, l, last); + if (!add) { + ch.add_len += l; + ch.add_cnt++; + } else { + if (ch.add) { + filechanges.add_change(ch); + ch.del_cnt = 0; + } + ch.offset += ch.add_cnt; + ch.add = add; + ch.add_len = l; + ch.add_cnt = 1; + } + } + } + } while(f.ReadLine(buffer, sizeof(buffer))); + return true; + } + + void write_diff(FileFd &f) + { + unsigned long long line = 0; + std::list<struct Change>::reverse_iterator ch; + for (ch = filechanges.rbegin(); ch != filechanges.rend(); ++ch) { + line += ch->offset + ch->del_cnt; + } + + for (ch = filechanges.rbegin(); ch != filechanges.rend(); ++ch) { + std::list<struct Change>::reverse_iterator mg_i, mg_e = ch; + while (ch->del_cnt == 0 && ch->offset == 0) + { + ++ch; + if (unlikely(ch == filechanges.rend())) + return; + } + line -= ch->del_cnt; + std::string buf; + if (ch->add_cnt > 0) { + if (ch->del_cnt == 0) { + strprintf(buf, "%llua\n", line); + } else if (ch->del_cnt == 1) { + strprintf(buf, "%lluc\n", line+1); + } else { + strprintf(buf, "%llu,%lluc\n", line+1, line+ch->del_cnt); + } + f.Write(buf.c_str(), buf.length()); + + mg_i = ch; + do { + dump_mem(f, mg_i->add, mg_i->add_len, NULL); + } while (mg_i-- != mg_e); + + buf = ".\n"; + f.Write(buf.c_str(), buf.length()); + } else if (ch->del_cnt == 1) { + strprintf(buf, "%llud\n", line+1); + f.Write(buf.c_str(), buf.length()); + } else if (ch->del_cnt > 1) { + strprintf(buf, "%llu,%llud\n", line+1, line+ch->del_cnt); + f.Write(buf.c_str(), buf.length()); + } + line -= ch->offset; + } + } + + void apply_against_file(FileFd &out, FileFd &in, + Hashes * const start_hash = nullptr, Hashes * const end_hash = nullptr) + { + std::list<struct Change>::iterator ch; + for (ch = filechanges.begin(); ch != filechanges.end(); ++ch) { + dump_lines(out, in, ch->offset, start_hash, end_hash); + skip_lines(in, ch->del_cnt, start_hash); + if (ch->add_len != 0) + dump_mem(out, ch->add, ch->add_len, end_hash); + } + dump_rest(out, in, start_hash, end_hash); + out.Flush(); + } +}; + +class RredMethod : public aptMethod { + private: + bool Debug; + + struct PDiffFile { + std::string FileName; + HashStringList ExpectedHashes; + PDiffFile(std::string const &FileName, HashStringList const &ExpectedHashes) : + FileName(FileName), ExpectedHashes(ExpectedHashes) {} + }; + + HashStringList ReadExpectedHashesForPatch(unsigned int const patch, std::string const &Message) + { + HashStringList ExpectedHashes; + for (char const * const * type = HashString::SupportedHashes(); *type != NULL; ++type) + { + std::string tagname; + strprintf(tagname, "Patch-%d-%s-Hash", patch, *type); + std::string const hashsum = LookupTag(Message, tagname.c_str()); + if (hashsum.empty() == false) + ExpectedHashes.push_back(HashString(*type, hashsum)); + } + return ExpectedHashes; + } + + protected: + virtual bool URIAcquire(std::string const &Message, FetchItem *Itm) APT_OVERRIDE { + Debug = DebugEnabled(); + URI Get = Itm->Uri; + std::string Path = Get.Host + Get.Path; // rred:/path - no host + + FetchResult Res; + Res.Filename = Itm->DestFile; + if (Itm->Uri.empty()) + { + Path = Itm->DestFile; + Itm->DestFile.append(".result"); + } else + URIStart(Res); + + std::vector<PDiffFile> patchfiles; + Patch patch; + + HashStringList StartHashes; + for (char const * const * type = HashString::SupportedHashes(); *type != nullptr; ++type) + { + std::string tagname; + strprintf(tagname, "Start-%s-Hash", *type); + std::string const hashsum = LookupTag(Message, tagname.c_str()); + if (hashsum.empty() == false) + StartHashes.push_back(HashString(*type, hashsum)); + } + + if (FileExists(Path + ".ed") == true) + { + HashStringList const ExpectedHashes = ReadExpectedHashesForPatch(0, Message); + std::string const FileName = Path + ".ed"; + if (ExpectedHashes.usable() == false) + return _error->Error("No hashes found for uncompressed patch: %s", FileName.c_str()); + patchfiles.push_back(PDiffFile(FileName, ExpectedHashes)); + } + else + { + _error->PushToStack(); + std::vector<std::string> patches = GetListOfFilesInDir(flNotFile(Path), "gz", true, false); + _error->RevertToStack(); + + std::string const baseName = Path + ".ed."; + unsigned int seen_patches = 0; + for (std::vector<std::string>::const_iterator p = patches.begin(); + p != patches.end(); ++p) + { + if (p->compare(0, baseName.length(), baseName) == 0) + { + HashStringList const ExpectedHashes = ReadExpectedHashesForPatch(seen_patches, Message); + if (ExpectedHashes.usable() == false) + return _error->Error("No hashes found for uncompressed patch %d: %s", seen_patches, p->c_str()); + patchfiles.push_back(PDiffFile(*p, ExpectedHashes)); + ++seen_patches; + } + } + } + + std::string patch_name; + for (std::vector<PDiffFile>::iterator I = patchfiles.begin(); + I != patchfiles.end(); + ++I) + { + patch_name = I->FileName; + if (Debug == true) + std::clog << "Patching " << Path << " with " << patch_name + << std::endl; + + FileFd p; + Hashes patch_hash(I->ExpectedHashes); + // all patches are compressed, even if the name doesn't reflect it + if (p.Open(patch_name, FileFd::ReadOnly, FileFd::Gzip) == false || + patch.read_diff(p, &patch_hash) == false) + { + _error->DumpErrors(std::cerr, GlobalError::DEBUG, false); + return false; + } + p.Close(); + HashStringList const hsl = patch_hash.GetHashStringList(); + if (hsl != I->ExpectedHashes) + return _error->Error("Hash Sum mismatch for uncompressed patch %s", patch_name.c_str()); + } + + if (Debug == true) + std::clog << "Applying patches against " << Path + << " and writing results to " << Itm->DestFile + << std::endl; + + FileFd inp, out; + if (inp.Open(Path, FileFd::ReadOnly, FileFd::Extension) == false) + { + if (Debug == true) + std::clog << "FAILED to open inp " << Path << std::endl; + return _error->Error("Failed to open inp %s", Path.c_str()); + } + if (out.Open(Itm->DestFile, FileFd::WriteOnly | FileFd::Create | FileFd::Empty | FileFd::BufferedWrite, FileFd::Extension) == false) + { + if (Debug == true) + std::clog << "FAILED to open out " << Itm->DestFile << std::endl; + return _error->Error("Failed to open out %s", Itm->DestFile.c_str()); + } + + Hashes end_hash(Itm->ExpectedHashes); + if (StartHashes.usable()) + { + Hashes start_hash(StartHashes); + patch.apply_against_file(out, inp, &start_hash, &end_hash); + if (start_hash.GetHashStringList() != StartHashes) + _error->Error("The input file hadn't the expected hash!"); + } + else + patch.apply_against_file(out, inp, nullptr, &end_hash); + + out.Close(); + inp.Close(); + + if (_error->PendingError() == true) { + if (Debug == true) + std::clog << "FAILED to read or write files" << std::endl; + return false; + } + + if (Debug == true) { + std::clog << "rred: finished file patching of " << Path << "." << std::endl; + } + + struct stat bufbase, bufpatch; + if (stat(Path.c_str(), &bufbase) != 0 || + stat(patch_name.c_str(), &bufpatch) != 0) + return _error->Errno("stat", _("Failed to stat %s"), Path.c_str()); + + struct timeval times[2]; + times[0].tv_sec = bufbase.st_atime; + times[1].tv_sec = bufpatch.st_mtime; + times[0].tv_usec = times[1].tv_usec = 0; + if (utimes(Itm->DestFile.c_str(), times) != 0) + return _error->Errno("utimes",_("Failed to set modification time")); + + if (stat(Itm->DestFile.c_str(), &bufbase) != 0) + return _error->Errno("stat", _("Failed to stat %s"), Itm->DestFile.c_str()); + + Res.LastModified = bufbase.st_mtime; + Res.Size = bufbase.st_size; + Res.TakeHashes(end_hash); + URIDone(Res); + + return true; + } + + public: + RredMethod() : aptMethod("rred", "2.0", SendConfig), Debug(false) {} +}; + +int main(int argc, char **argv) +{ + int i; + bool just_diff = true; + bool test = false; + Patch patch; + + if (argc <= 1) { + return RredMethod().Run(); + } + + // Usage: rred -t input output diff ... + if (argc > 1 && strcmp(argv[1], "-t") == 0) { + // Read config files so we see compressors. + pkgInitConfig(*_config); + just_diff = false; + test = true; + i = 4; + } else if (argc > 1 && strcmp(argv[1], "-f") == 0) { + just_diff = false; + i = 2; + } else { + i = 1; + } + + for (; i < argc; i++) { + FileFd p; + if (p.Open(argv[i], FileFd::ReadOnly) == false) { + _error->DumpErrors(std::cerr); + exit(1); + } + if (patch.read_diff(p, NULL) == false) + { + _error->DumpErrors(std::cerr); + exit(2); + } + } + + if (test) { + FileFd out, inp; + std::cerr << "Patching " << argv[2] << " into " << argv[3] << "\n"; + inp.Open(argv[2], FileFd::ReadOnly,FileFd::Extension); + out.Open(argv[3], FileFd::WriteOnly | FileFd::Create | FileFd::Empty | FileFd::BufferedWrite, FileFd::Extension); + patch.apply_against_file(out, inp); + out.Close(); + } else if (just_diff) { + FileFd out; + out.OpenDescriptor(STDOUT_FILENO, FileFd::WriteOnly | FileFd::Create); + patch.write_diff(out); + out.Close(); + } else { + FileFd out, inp; + out.OpenDescriptor(STDOUT_FILENO, FileFd::WriteOnly | FileFd::Create | FileFd::BufferedWrite); + inp.OpenDescriptor(STDIN_FILENO, FileFd::ReadOnly); + patch.apply_against_file(out, inp); + out.Close(); + } + return 0; +} |