intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 95 insertions, 0 deletions

diff --git a/library/cpp/string_utils/parse_size/parse_size.cpp b/library/cpp/string_utils/parse_size/parse_size.cpp
new file mode 100644
index 0000000000..39188d560b
--- /dev/null
+++ b/library/cpp/string_utils/parse_size/parse_size.cpp
@@ -0,0 +1,95 @@
+#include "parse_size.h"
+
+#include <util/generic/yexception.h>
+#include <util/generic/ylimits.h>
+#include <util/string/cast.h>
+#include <util/stream/output.h>
+
+namespace {
+    enum ESuffixShifts {
+        ESS_KILO_BYTES = 10,
+        ESS_MEGA_BYTES = 20,
+        ESS_GIGA_BYTES = 30,
+        ESS_TERA_BYTES = 40,
+    };
+
+    bool TryShiftValue(ui64& value, ui64 shift) {
+        if (value > (Max<ui64>() >> shift)) {
+            return false;
+        }
+
+        value <<= shift;
+        return true;
+    }
+
+    ui64 ShiftValue(ui64 value, ui64 shift) {
+        if (!TryShiftValue(value, shift)) {
+            ythrow yexception() << "value overflow '" << value << " << " << shift << "'";
+        } else {
+            return value;
+        }
+    }
+
+}
+
+namespace NSize {
+    ui64 ParseSize(TStringBuf str) {
+        if (! str.size())
+            ythrow yexception() << "Wrong size " << str;
+        char suff = tolower(str[str.size() - 1]);
+        if (isdigit(suff))
+            return FromString<ui64>(str);
+        ui64 shift = 1;
+        switch (suff) {
+            case 'k':
+                shift = ESS_KILO_BYTES;
+                break;
+            case 'm':
+                shift = ESS_MEGA_BYTES;
+                break;
+            case 'g':
+                shift = ESS_GIGA_BYTES;
+                break;
+            case 't':
+                shift = ESS_TERA_BYTES;
+                break;
+            default:
+                ythrow yexception() << "Unknown suffix " << str;
+        }
+
+        ui64 value = FromString<ui64>(str.substr(0, str.size() - 1));
+
+        if (!TryShiftValue(value, shift)) {
+            ythrow yexception() << "Value overflow " << str;
+        } else {
+            return value;
+        }
+    }
+
+    TSize FromKiloBytes(ui64 value) {
+        return TSize(ShiftValue(value, ESS_KILO_BYTES));
+    }
+
+    TSize FromMegaBytes(ui64 value) {
+        return TSize(ShiftValue(value, ESS_MEGA_BYTES));
+    }
+
+    TSize FromGigaBytes(ui64 value) {
+        return TSize(ShiftValue(value, ESS_GIGA_BYTES));
+    }
+
+    TSize FromTeraBytes(ui64 value) {
+        return TSize(ShiftValue(value, ESS_TERA_BYTES));
+    }
+
+}
+
+template <>
+NSize::TSize FromStringImpl<NSize::TSize>(const char* data, size_t len) {
+    return NSize::TSize(NSize::ParseSize(TStringBuf(data, len)));
+}
+
+template <>
+void Out<NSize::TSize>(IOutputStream& os, const NSize::TSize& size) {
+    os << size.GetValue();
+}