intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 67 insertions, 0 deletions

diff --git a/library/cpp/on_disk/chunks/chunked_helpers.cpp b/library/cpp/on_disk/chunks/chunked_helpers.cpp
new file mode 100644
index 0000000000..b7adba2753
--- /dev/null
+++ b/library/cpp/on_disk/chunks/chunked_helpers.cpp
@@ -0,0 +1,67 @@
+#include <util/ysaveload.h>
+
+#include "chunked_helpers.h"
+
+TBlob GetBlock(const TBlob& blob, size_t index) {
+    TChunkedDataReader reader(blob);
+    if (index >= reader.GetBlocksCount())
+        ythrow yexception() << "index " << index << " is >= than block count " << reader.GetBlocksCount();
+    size_t begin = (const char*)reader.GetBlock(index) - (const char*)blob.Data();
+    return blob.SubBlob(begin, begin + reader.GetBlockLen(index));
+}
+
+/*************************** TNamedChunkedDataReader ***************************/
+
+static const char* NamedChunkedDataMagic = "NamedChunkedData";
+
+TNamedChunkedDataReader::TNamedChunkedDataReader(const TBlob& blob)
+    : TChunkedDataReader(blob)
+{
+    if (TChunkedDataReader::GetBlocksCount() < 1)
+        throw yexception() << "Too few blocks";
+
+    size_t block = TChunkedDataReader::GetBlocksCount() - 1;
+    size_t magicLen = strlen(NamedChunkedDataMagic);
+    if (GetBlockLen(block) < magicLen || memcmp(GetBlock(block), NamedChunkedDataMagic, magicLen) != 0)
+        throw yexception() << "Not a valid named chunked data file";
+
+    TMemoryInput input(static_cast<const char*>(GetBlock(block)) + magicLen, GetBlockLen(block) - magicLen);
+    Load(&input, Names);
+
+    size_t index = 0;
+    for (TVector<TString>::const_iterator it = Names.begin(); it != Names.end(); ++it, ++index) {
+        if (!it->empty())
+            NameToIndex[*it] = index;
+    }
+}
+
+/*************************** TNamedChunkedDataWriter ***************************/
+
+TNamedChunkedDataWriter::TNamedChunkedDataWriter(IOutputStream& slave)
+    : TChunkedDataWriter(slave)
+{
+}
+
+TNamedChunkedDataWriter::~TNamedChunkedDataWriter() {
+}
+
+void TNamedChunkedDataWriter::NewBlock() {
+    NewBlock("");
+}
+
+void TNamedChunkedDataWriter::NewBlock(const TString& name) {
+    if (!name.empty()) {
+        if (NameToIndex.count(name) != 0)
+            throw yexception() << "Block name is not unique";
+        NameToIndex[name] = Names.size();
+    }
+    Names.push_back(name);
+    TChunkedDataWriter::NewBlock();
+}
+
+void TNamedChunkedDataWriter::WriteFooter() {
+    NewBlock("");
+    Write(NamedChunkedDataMagic);
+    Save(this, Names);
+    TChunkedDataWriter::WriteFooter();
+}