Wrap sqlite3_blob_read and sqlite3_blob_write.

3 files changed, 115 insertions, 0 deletions

diff --git a/src/generic/util/sqlite.cc b/src/generic/util/sqlite.cc
index e4cbff37..0d138ae2 100644
--- a/src/generic/util/sqlite.cc
+++ b/src/generic/util/sqlite.cc
@@ -413,5 +413,30 @@ namespace aptitude
 	sqlite3_blob_close(handle);
       parent.active_blobs.erase(this);
     }
+
+    int blob::size()
+    {
+      return sqlite3_blob_bytes(handle);
+    }
+
+    void blob::read(int offset, void *out, int length)
+    {
+      const int result = sqlite3_blob_read(handle, out, length, offset);
+      if(result != SQLITE_OK)
+	{
+	  std::string msg(parent.get_error());
+	  throw exception(msg, result);
+	}
+    }
+
+    void blob::write(int offset, const void *out, int length)
+    {
+      const int result = sqlite3_blob_write(handle, out, length, offset);
+      if(result != SQLITE_OK)
+	{
+	  std::string msg(parent.get_error());
+	  throw exception(msg, result);
+	}
+    }
   }
 }
diff --git a/src/generic/util/sqlite.h b/src/generic/util/sqlite.h
index 884385d8..abe640f6 100644
--- a/src/generic/util/sqlite.h
+++ b/src/generic/util/sqlite.h
@@ -490,6 +490,36 @@ namespace aptitude
 	   sqlite3_int64 row,
 	   bool readWrite = true);
 
+      /** \brief Retrieve the size of the BLOB in bytes. */
+      int size();
+
+      /** \brief Read some data from the BLOB.
+       *
+       *  \param offset   The byte offset at which to start reading.
+       *  \param out      The memory location at which to begin storing
+       *                  the data that was read.
+       *  \param length   The number of bytes of data to read.
+       *
+       *  If there are fewer than "length" bytes following "offset" in
+       *  the BLOB, this operation throws an exception.  If the BLOB's
+       *  row has been modified, this operation throws an exception
+       *  with the error code SQLITE_ABORT.
+       */
+      void read(int offset, void *out, int length);
+
+      /** \brief Write some data into the BLOB.
+       *
+       *  \param offset The byte offset at which to start writing.
+       *  \param in     The data to write into the BLOB.
+       *  \param length The number of bytes of data to write.
+       *
+       *  If there are fewer than "length" bytes following "offset" in
+       *  the BLOB, this operation throws an exception.  If the BLOB's
+       *  row has been modified, this operation throws an exception
+       *  with the error code SQLITE_ABORT.
+       */
+      void write(int offset, const void *in, int length);
+
       ~blob();
     };
   }
diff --git a/tests/test_sqlite.cc b/tests/test_sqlite.cc
index 1ff034bf..2a7e174f 100644
--- a/tests/test_sqlite.cc
+++ b/tests/test_sqlite.cc
@@ -429,3 +429,63 @@ BOOST_FIXTURE_TEST_CASE(testOpenBlob, test_blob_fixture)
 			       100),
 		    exception);
 }
+
+BOOST_FIXTURE_TEST_CASE(testBlobSize, test_blob_fixture)
+{
+  boost::shared_ptr<blob> b = blob::open(*tmpdb,
+					 "main",
+					 "test",
+					 "C",
+					 blob_rowid);
+
+  BOOST_CHECK_EQUAL(b->size(), 2);
+}
+
+BOOST_FIXTURE_TEST_CASE(testBlobRead, test_blob_fixture)
+{
+  boost::shared_ptr<blob> b = blob::open(*tmpdb,
+					 "main",
+					 "test",
+					 "C",
+					 blob_rowid);
+
+  char contents[3];
+  const char expected[] = { 0x54, 0x12 };
+  b->read(0, contents, 2);
+  BOOST_CHECK_EQUAL_COLLECTIONS(contents, contents + 2,
+				expected, expected + 2);
+  b->read(0, contents, 2);
+  BOOST_CHECK_EQUAL_COLLECTIONS(contents, contents + 2,
+				expected, expected + 2);
+
+  BOOST_CHECK_THROW(b->read(0, contents, 3), exception);
+}
+
+BOOST_FIXTURE_TEST_CASE(testBlobWrite, test_blob_fixture)
+{
+  const char data[2] = { 0x54, 0x11 };
+  {
+    boost::shared_ptr<blob> b = blob::open(*tmpdb,
+					   "main",
+					   "test",
+					   "C",
+					   blob_rowid);
+
+    b->write(1, data + 1, 1);
+    BOOST_CHECK_THROW(b->write(1, data, 2), exception);
+  }
+
+  boost::shared_ptr<statement> stmt =
+    statement::prepare(*tmpdb, "select C from test where rowid = ?");
+  stmt->bind_int64(1, blob_rowid);
+  BOOST_REQUIRE(stmt->step());
+
+  int len = -1;
+  const void *val = stmt->get_blob(0, len);
+  BOOST_CHECK_EQUAL(len, sizeof(data));
+  BOOST_CHECK_EQUAL_COLLECTIONS(data, data + sizeof(data),
+				reinterpret_cast<const char *>(val),
+				reinterpret_cast<const char *>(val) + len);
+
+  BOOST_CHECK(!stmt->step());
+}