-//
-// SuperBlob - a typed bag of Blobs
-//
-#ifndef _H_SUPERBLOB
-#define _H_SUPERBLOB
-
-#include <security_utilities/blob.h>
-#include <map>
-
-namespace Security {
-
-
-//
-// A SuperBlob is a Blob that contains multiple sub-Blobs of varying type.
-// The SuperBlob is contiguous and contains a directory of its sub-blobs.
-// A Maker is included.
-//
-// SuperBlobCore lets you define your own SuperBlob type. To just use a generic
-// SuperBlob, use SuperBlob<> below.
-//
-template <class _BlobType, uint32_t _magic, class _Type>
-class SuperBlobCore: public Blob<_BlobType, _magic> {
-public:
- class Maker; friend class Maker;
-
- typedef _Type Type;
-
- // echoes from parent BlobCore (the C++ type system is too restrictive here)
- typedef BlobCore::Offset Offset;
- template <class BlobType> BlobType *at(Offset offset) { return BlobCore::at<BlobType>(offset); }
- template <class BlobType> const BlobType *at(Offset offset) const { return BlobCore::at<BlobType>(offset); }
-
- void setup(size_t size, unsigned count)
- { this->initialize(size); this->mCount = count; }
-
- struct Index {
- Endian<Type> type; // type of sub-Blob
- Endian<Offset> offset; // starting offset
- };
-
- bool validateBlob(size_t maxSize = 0) const;
-
- unsigned count() const { return mCount; }
-
- // access by index number
- Type type(unsigned n) const { assert(n < mCount); return mIndex[n].type; }
- const BlobCore *blob(unsigned n) const
- { assert(n < mCount); return mIndex[n].offset ? at<const BlobCore>(mIndex[n].offset) : NULL; }
- template <class BlobType>
- const BlobType *blob(unsigned n) const { return BlobType::specific(blob(n)); }
-
- // access by index type (assumes unique types)
- const BlobCore *find(Type type) const;
- template <class BlobType>
- const BlobType *find(Type type) const { return BlobType::specific(find(type)); }
-
-private:
- Endian<uint32_t> mCount; // number of sub-Blobs following
- Index mIndex[0]; // <count> IndexSlot structures
- // followed by sub-Blobs, packed and ordered in an undefined way
-};
-
-
-template <class _BlobType, uint32_t _magic, class _Type>
-inline bool SuperBlobCore<_BlobType, _magic, _Type>::validateBlob(size_t maxSize /* = 0 */) const
-{
- unsigned count = mCount;
- size_t ixLimit = sizeof(SuperBlobCore) + count * sizeof(Index); // end of index vector
- if (!BlobCore::validateBlob(_magic, ixLimit, maxSize))
- return false;
- for (const Index *ix = mIndex + count - 1; ix >= mIndex; ix--) {
- Offset offset = ix->offset;
- if (offset) // if non-null
- if (offset < ixLimit // offset not too small
- || offset + sizeof(BlobCore) > this->length() // fits Blob header (including length field)
- || offset + at<const BlobCore>(offset)->length() > this->length()) // fits entire blob
- return false;
- }
- return true;
-}
-
-
-//
-// A generic SuperBlob ready for use. You still need to specify a magic number.
-//
-template <uint32_t _magic, class _Type = uint32_t>
-class SuperBlob : public SuperBlobCore<SuperBlob<_magic, _Type>, _magic, _Type> {
-};
-
-
-template <class _BlobType, uint32_t _magic, class _Type>
-const BlobCore *SuperBlobCore<_BlobType, _magic, _Type>::find(Type type) const
-{
- for (unsigned slot = 0; slot < mCount; slot++)
- if (mIndex[slot].type == type)
- return mIndex[slot].offset ? at<const BlobCore>(mIndex[slot].offset) : NULL;
- return NULL; // not found
-}
-
-
-//
-// A SuperBlob::Maker simply assembles multiple Blobs into a single, indexed
-// super-blob. Just add() sub-Blobs by type and call make() to get
-// the result, malloc'ed. A Maker is not resettable.
-// Maker can repeatedly make SuperBlobs from the same (cached) inputs.
-// It can also tell you how big its output will be, given established contents
-// plus (optional) additional sizes of blobs yet to come.
-//
-template <class _BlobType, uint32_t _magic, class _Type>
-class SuperBlobCore<_BlobType, _magic, _Type>::Maker {
-public:
- Maker() { }
-
- Maker(const Maker &src)
- {
- for (typename BlobMap::iterator it = mPieces.begin(); it != mPieces.end(); ++it)
- mPieces.insert(make_pair(it->first, it->second->clone()));
- }
-
- ~Maker()
- {
- for (typename BlobMap::iterator it = mPieces.begin(); it != mPieces.end(); ++it)
- ::free(it->second);
- }
-
- void add(Type type, BlobCore *blob); // takes ownership of blob
- void add(const _BlobType *blobs); // copies all blobs
- void add(const Maker &maker); // ditto
-
- bool contains(Type type) const // see if we have this type already
- { return mPieces.find(type) != mPieces.end(); }
- BlobCore *get(Type type) const
- {
- typename BlobMap::const_iterator it = mPieces.find(type);
- return (it == mPieces.end()) ? NULL : it->second;
- }
-
- size_t size(size_t size1 = 0, ...) const; // size with optional additional blob sizes
- _BlobType *make() const; // create (malloc) and return SuperBlob
- _BlobType *operator () () const { return make(); }
-
-private:
- typedef std::map<Type, BlobCore *> BlobMap;
- BlobMap mPieces;
-};
-
-
-//
-// Add a Blob to a SuperBlob::Maker.
-// This takes ownership of the blob, which must have been malloc'ed.
-// Any previous value set for this Type will be freed immediately.
-//
-template <class _BlobType, uint32_t _magic, class _Type>
-void SuperBlobCore<_BlobType, _magic, _Type>::Maker::add(Type type, BlobCore *blob)
-{
- pair<typename BlobMap::iterator, bool> r = mPieces.insert(make_pair(type, blob));
- if (!r.second) { // already there
- secdebug("superblob", "Maker %p replaces type=%d", this, type);
- ::free(r.first->second);
- r.first->second = blob;
- }
-}
-
-template <class _BlobType, uint32_t _magic, class _Type>
-void SuperBlobCore<_BlobType, _magic, _Type>::Maker::add(const _BlobType *blobs)
-{
- for (uint32_t ix = 0; ix < blobs->mCount; ix++)
- this->add(blobs->mIndex[ix].type, blobs->blob(ix)->clone());
-}
-
-template <class _BlobType, uint32_t _magic, class _Type>
-void SuperBlobCore<_BlobType, _magic, _Type>::Maker::add(const Maker &maker)
-{
- for (typename BlobMap::const_iterator it = maker.mPieces.begin(); it != maker.mPieces.end(); ++it)
- this->add(it->first, it->second->clone());
-}
-
-
-//
-// Calculate the size the new SuperBlob would have, given the contents of the Maker
-// so far, plus additional blobs with the sizes given.
-//
-template <class _BlobType, uint32_t _magic, class _Type>
-size_t SuperBlobCore<_BlobType, _magic, _Type>::Maker::size(size_t size1, ...) const
-{
- // count established blobs
- size_t count = mPieces.size();
- size_t total = 0;
- for (typename BlobMap::const_iterator it = mPieces.begin(); it != mPieces.end(); ++it)
- total += it->second->length();
-
- // add preview blob sizes to calculation (if any)
- if (size1) {
- va_list args;
- va_start(args, size1);
- do {
- count++;
- total += size1;
- size1 = va_arg(args, size_t);
- } while (size1);
- va_end(args);
- }
-
- return sizeof(SuperBlobCore) + count * sizeof(Index) + total;
-}
-
-
-//
-// Finish SuperBlob construction and return the new, malloc'ed, SuperBlob.
-// This can be done repeatedly.
-//
-template <class _BlobType, uint32_t _magic, class _Type>
-_BlobType *SuperBlobCore<_BlobType, _magic, _Type>::Maker::make() const
-{
- Offset pc = (Offset)(sizeof(SuperBlobCore) + mPieces.size() * sizeof(Index));
- Offset total = (Offset)size();
- _BlobType *result = (_BlobType *)malloc(total);
- if (!result)
- UnixError::throwMe(ENOMEM);
- result->setup(total, (unsigned)mPieces.size());
- unsigned n = 0;
- for (typename BlobMap::const_iterator it = mPieces.begin(); it != mPieces.end(); ++it) {
- result->mIndex[n].type = it->first;
- result->mIndex[n].offset = pc;
- memcpy(result->template at<unsigned char>(pc), it->second, it->second->length());
- pc += it->second->length();
- n++;
- }
- secdebug("superblob", "Maker %p assembles %ld blob(s) into %p (size=%d)",
- this, mPieces.size(), result, total);
- return result;
-}
-
-
-} // Security
-
-#endif //_H_SUPERBLOB
projects / apple / security.git / blobdiff