ftparchive/contents.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: contents.cc,v 1.4 2003/02/10 07:34:41 doogie Exp $
   4 /* ######################################################################
   5
   6    contents - Archive contents generator
   7
   8    The GenContents class is a back end for an archive contents generator.
   9    It takes a list of per-deb file name and merges it into a memory
  10    database of all previous output. This database is stored as a set
  11    of binary trees linked across directories to form a tree of all files+dirs
  12    given to it. The tree will also be sorted as it is built up thus
  13    removing the massive sort time overhead.
  14
  15    By breaking all the pathnames into components and storing them
  16    separately a space saving is realized by not duplicating the string
  17    over and over again. Ultimately this saving is sacrificed to storage of
  18    the tree structure itself but the tree structure yields a speed gain
  19    in the sorting and processing. Ultimately it takes about 5 seconds to
  20    do 141000 nodes and about 5 meg of ram.
  21
  22    The tree looks something like:
  23
  24      usr/
  25       / \             / libslang
  26    bin/ lib/ --> libc6
  27         /   \         \ libfoo
  28    games/  sbin/
  29
  30    The ---> is the DirDown link
  31
  32
  33    ##################################################################### */
  34                                                                         /*}}}*/
  35 // Include Files                                                        /*{{{*/
  36 #include <config.h>
  37
  38 #include <apt-pkg/debfile.h>
  39 #include <apt-pkg/extracttar.h>
  40 #include <apt-pkg/error.h>
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44 #include <malloc.h>
  45
  46 #include <apti18n.h>
  47 #include "contents.h"
  48                                                                         /*}}}*/
  49
  50 // GenContents::~GenContents - Free allocated memory                    /*{{{*/
  51 // ---------------------------------------------------------------------
  52 /* Since all our allocations are static big-block allocations all that is
  53    needed is to free all of them. */
  54 GenContents::~GenContents()
  55 {
  56    while (BlockList != 0)
  57    {
  58       BigBlock *Old = BlockList;
  59       BlockList = Old->Next;
  60       free(Old->Block);
  61       delete Old;
  62    }
  63 }
  64                                                                         /*}}}*/
  65 // GenContents::Mystrdup - Custom strdup                                /*{{{*/
  66 // ---------------------------------------------------------------------
  67 /* This strdup also uses a large block allocator to eliminate glibc
  68    overhead */
  69 char *GenContents::Mystrdup(const char *From)
  70 {
  71    unsigned int Len = strlen(From) + 1;
  72    if (StrLeft <= Len)
  73    {
  74       StrLeft = 4096*10;
  75       StrPool = (char *)malloc(StrLeft);
  76
  77       BigBlock *Block = new BigBlock;
  78       Block->Block = StrPool;
  79       Block->Next = BlockList;
  80       BlockList = Block;
  81    }
  82
  83    memcpy(StrPool,From,Len);
  84    StrLeft -= Len;
  85
  86    char *Res = StrPool;
  87    StrPool += Len;
  88    return Res;
  89 }
  90                                                                         /*}}}*/
  91 // GenContents::Node::operator new - Big block allocator                /*{{{*/
  92 // ---------------------------------------------------------------------
  93 /* This eliminates glibc's malloc overhead by allocating large blocks and
  94    having a continuous set of Nodes. This takes about 8 bytes off each nodes
  95    space needs. Freeing is not supported. */
  96 void *GenContents::Node::operator new(size_t Amount,GenContents *Owner)
  97 {
  98    if (Owner->NodeLeft == 0)
  99    {
 100       Owner->NodeLeft = 10000;
 101       Owner->NodePool = (Node *)malloc(Amount*Owner->NodeLeft);
 102       BigBlock *Block = new BigBlock;
 103       Block->Block = Owner->NodePool;
 104       Block->Next = Owner->BlockList;
 105       Owner->BlockList = Block;
 106    }
 107
 108    Owner->NodeLeft--;
 109    return Owner->NodePool++;
 110 }
 111                                                                         /*}}}*/
 112 // GenContents::Grab - Grab a new node representing Name under Top      /*{{{*/
 113 // ---------------------------------------------------------------------
 114 /* This grabs a new node representing the pathname component Name under
 115    the node Top. The node is given the name Package. It is assumed that Name
 116    is inside of top. If a duplicate already entered name is found then
 117    a note is made on the Dup list and the previous in-tree node is returned. */
 118 GenContents::Node *GenContents::Grab(GenContents::Node *Top,const char *Name,
 119                         const char *Package)
 120 {
 121    /* We drop down to the next dir level each call. This simplifies
 122       the calling routine */
 123    if (Top->DirDown == 0)
 124    {
 125       Node *Item = new(this) Node;
 126       Item->Path = Mystrdup(Name);
 127       Item->Package = Package;
 128       Top->DirDown = Item;
 129       return Item;
 130    }
 131    Top = Top->DirDown;
 132
 133    int Res;
 134    while (1)
 135    {
 136       Res = strcmp(Name,Top->Path);
 137
 138       // Collision!
 139       if (Res == 0)
 140       {
 141          // See if this the the same package (multi-version dup)
 142          if (Top->Package == Package ||
 143              strcasecmp(Top->Package,Package) == 0)
 144             return Top;
 145
 146          // Look for an already existing Dup
 147          for (Node *I = Top->Dups; I != 0; I = I->Dups)
 148             if (I->Package == Package ||
 149                 strcasecmp(I->Package,Package) == 0)
 150                return Top;
 151
 152          // Add the dup in
 153          Node *Item = new(this) Node;
 154          Item->Path = Top->Path;
 155          Item->Package = Package;
 156          Item->Dups = Top->Dups;
 157          Top->Dups = Item;
 158          return Top;
 159       }
 160
 161       // Continue to traverse the tree
 162       if (Res < 0)
 163       {
 164          if (Top->BTreeLeft == 0)
 165             break;
 166          Top = Top->BTreeLeft;
 167       }
 168       else
 169       {
 170          if (Top->BTreeRight == 0)
 171             break;
 172          Top = Top->BTreeRight;
 173       }
 174    }
 175
 176    // The item was not found in the tree
 177    Node *Item = new(this) Node;
 178    Item->Path = Mystrdup(Name);
 179    Item->Package = Package;
 180
 181    // Link it into the tree
 182    if (Res < 0)
 183    {
 184       Item->BTreeLeft = Top->BTreeLeft;
 185       Top->BTreeLeft = Item;
 186    }
 187    else
 188    {
 189       Item->BTreeRight = Top->BTreeRight;
 190       Top->BTreeRight = Item;
 191    }
 192
 193    return Item;
 194 }
 195                                                                         /*}}}*/
 196 // GenContents::Add - Add a path to the tree                            /*{{{*/
 197 // ---------------------------------------------------------------------
 198 /* This takes a full pathname and adds it into the tree. We split the
 199    pathname into directory fragments adding each one as we go. Technically
 200    in output from tar this should result in hitting previous items. */
 201 void GenContents::Add(const char *Dir,const char *Package)
 202 {
 203    Node *Root = &this->Root;
 204
 205    // Drop leading slashes
 206    while (*Dir == '/' && *Dir != 0)
 207       Dir++;
 208
 209    // Run over the string and grab out each bit up to and including a /
 210    const char *Start = Dir;
 211    const char *I = Dir;
 212    while (*I != 0)
 213    {
 214       if (*I != '/' || I - Start <= 1)
 215       {
 216          I++;
 217          continue;
 218       }
 219       I++;
 220
 221       // Copy the path fragment over
 222       char Tmp[1024];
 223       strncpy(Tmp,Start,I - Start);
 224       Tmp[I - Start] = 0;
 225
 226       // Grab a node for it
 227       Root = Grab(Root,Tmp,Package);
 228
 229       Start = I;
 230    }
 231
 232    // The final component if it does not have a trailing /
 233    if (I - Start >= 1)
 234       Root = Grab(Root,Start,Package);
 235 }
 236                                                                         /*}}}*/
 237 // GenContents::WriteSpace - Write a given number of white space chars  /*{{{*/
 238 // ---------------------------------------------------------------------
 239 /* We mod 8 it and write tabs where possible. */
 240 void GenContents::WriteSpace(FILE *Out,unsigned int Current,unsigned int Target)
 241 {
 242    if (Target <= Current)
 243       Target = Current + 1;
 244
 245    /* Now we write tabs so long as the next tab stop would not pass
 246       the target */
 247    for (; (Current/8 + 1)*8 < Target; Current = (Current/8 + 1)*8)
 248       fputc('\t',Out);
 249
 250    // Fill the last bit with spaces
 251    for (; Current < Target; Current++)
 252       fputc(' ',Out);
 253 }
 254                                                                         /*}}}*/
 255 // GenContents::Print - Display the tree                                /*{{{*/
 256 // ---------------------------------------------------------------------
 257 /* This is the final result function. It takes the tree and recursively
 258    calls itself and runs over each section of the tree printing out
 259    the pathname and the hit packages. We use Buf to build the pathname
 260    summed over all the directory parents of this node. */
 261 void GenContents::Print(FILE *Out)
 262 {
 263    char Buffer[1024];
 264    Buffer[0] = 0;
 265    DoPrint(Out,&Root,Buffer);
 266 }
 267 void GenContents::DoPrint(FILE *Out,GenContents::Node *Top, char *Buf)
 268 {
 269    if (Top == 0)
 270       return;
 271
 272    // Go left
 273    DoPrint(Out,Top->BTreeLeft,Buf);
 274
 275    // Print the current dir location and then descend to lower dirs
 276    char *OldEnd = Buf + strlen(Buf);
 277    if (Top->Path != 0)
 278    {
 279       strcat(Buf,Top->Path);
 280
 281       // Do not show the item if it is a directory with dups
 282       if (Top->Path[strlen(Top->Path)-1] != '/' /*|| Top->Dups == 0*/)
 283       {
 284          fputs(Buf,Out);
 285          WriteSpace(Out,strlen(Buf),60);
 286          for (Node *I = Top; I != 0; I = I->Dups)
 287          {
 288             if (I != Top)
 289                fputc(',',Out);
 290             fputs(I->Package,Out);
 291          }
 292          fputc('\n',Out);
 293       }
 294    }
 295
 296    // Go along the directory link
 297    DoPrint(Out,Top->DirDown,Buf);
 298    *OldEnd = 0;
 299
 300    // Go right
 301    DoPrint(Out,Top->BTreeRight,Buf);
 302 }
 303                                                                         /*}}}*/
 304
 305 // ContentsExtract::Read - Read the archive                             /*{{{*/
 306 // ---------------------------------------------------------------------
 307 /* */
 308 bool ContentsExtract::Read(debDebFile &Deb)
 309 {
 310    Reset();
 311    return Deb.ExtractArchive(*this);
 312 }
 313                                                                         /*}}}*/
 314 // ContentsExtract::DoItem - Extract an item                            /*{{{*/
 315 // ---------------------------------------------------------------------
 316 /* This just tacks the name onto the end of our memory buffer */
 317 bool ContentsExtract::DoItem(Item &Itm,int &Fd)
 318 {
 319    unsigned long Len = strlen(Itm.Name);
 320
 321    // Strip leading ./'s
 322    if (Itm.Name[0] == '.' && Itm.Name[1] == '/')
 323    {
 324       // == './'
 325       if (Len == 2)
 326          return true;
 327
 328       Len -= 2;
 329       Itm.Name += 2;
 330    }
 331
 332    // Allocate more storage for the string list
 333    if (CurSize + Len + 2 >= MaxSize || Data == 0)
 334    {
 335       if (MaxSize == 0)
 336          MaxSize = 512*1024/2;
 337       char *NewData = (char *)realloc(Data,MaxSize*2);
 338       if (NewData == 0)
 339          return _error->Error(_("realloc - Failed to allocate memory"));
 340       Data = NewData;
 341       MaxSize *= 2;
 342    }
 343
 344    strcpy(Data+CurSize,Itm.Name);
 345    CurSize += Len + 1;
 346    return true;
 347 }
 348                                                                         /*}}}*/
 349 // ContentsExtract::TakeContents - Load the contents data               /*{{{*/
 350 // ---------------------------------------------------------------------
 351 /* */
 352 bool ContentsExtract::TakeContents(const void *NewData,unsigned long long Length)
 353 {
 354    if (Length == 0)
 355    {
 356       CurSize = 0;
 357       return true;
 358    }
 359
 360    // Allocate more storage for the string list
 361    if (Length + 2 >= MaxSize || Data == 0)
 362    {
 363       if (MaxSize == 0)
 364          MaxSize = 512*1024/2;
 365       while (MaxSize*2 <= Length)
 366          MaxSize *= 2;
 367
 368       char *NewData = (char *)realloc(Data,MaxSize*2);
 369       if (NewData == 0)
 370          return _error->Error(_("realloc - Failed to allocate memory"));
 371       Data = NewData;
 372       MaxSize *= 2;
 373    }
 374    memcpy(Data,NewData,Length);
 375    CurSize = Length;
 376
 377    return Data[CurSize-1] == 0;
 378 }
 379                                                                         /*}}}*/
 380 // ContentsExtract::Add - Read the contents data into the sorter        /*{{{*/
 381 // ---------------------------------------------------------------------
 382 /* */
 383 void ContentsExtract::Add(GenContents &Contents,std::string const &Package)
 384 {
 385    const char *Start = Data;
 386    char *Pkg = Contents.Mystrdup(Package.c_str());
 387    for (const char *I = Data; I < Data + CurSize; I++)
 388    {
 389       if (*I == 0)
 390       {
 391          Contents.Add(Start,Pkg);
 392          Start = ++I;
 393       }
 394    }
 395 }
 396                                                                         /*}}}*/