Hi Muthu,
tried to reach you on IRC yesterday:
Feb 13 11:03:42 <sberg> muthusuba, 8f8bc0dcf3bc253ae49159d52db049767f476ced is
broken: (a) the general O[U]String::hashCode does sampling-only by design; if that's
not considered good these days we should change the implementation rather than add
another function (is 64-bit vs. 32-bit hash code of any added value? doubt it given
most hash maps will not be too big, anyway); (b) adding OString::hashCode64 but not
OUString::hashCode64? (c) rtl_str_hashCode64_WithLength must
Feb 13 11:03:42 <sberg> go into a LIBO_UDK_4.3 section in sal.map, not
UDK_3_0_0; (d) rtl_ustr_hashCode64_WithLength missing from sal.map; (e) missing
@since tags
Stephan
On 02/13/2014 08:41 AM, Muthu Subramanian wrote:
include/rtl/string.h | 18 ++++++++++++++++++
include/rtl/string.hxx | 13 +++++++++++++
include/rtl/ustring.h | 18 ++++++++++++++++++
sal/rtl/strtmpl.cxx | 13 +++++++++++++
sal/util/sal.map | 1 +
sd/source/core/sdpage2.cxx | 12 +-----------
6 files changed, 64 insertions(+), 11 deletions(-)
New commits:
commit 8f8bc0dcf3bc253ae49159d52db049767f476ced
Author: Muthu Subramanian <sumu...@collabora.com>
Date: Thu Feb 13 13:13:53 2014 +0530
Move string hash function into String class.
hashCode() seems to do sampling while creating the hash.
hashCode64() will not.
Change-Id: Id30f5a2a774cf5244dbc00da9649e95a532484be
diff --git a/include/rtl/string.h b/include/rtl/string.h
index 32344bf..71e0955 100644
--- a/include/rtl/string.h
+++ b/include/rtl/string.h
@@ -277,6 +277,24 @@ SAL_DLLPUBLIC sal_Int32 SAL_CALL rtl_str_hashCode(
SAL_DLLPUBLIC sal_Int32 SAL_CALL rtl_str_hashCode_WithLength(
const sal_Char * str, sal_Int32 len ) SAL_THROW_EXTERN_C();
+/** Return a hash code (64bit) for a string.
+
+ It is not allowed to store the hash code persistently, because later
+ versions could return other hash codes.
+
+ @param str
+ a string. Need not be null-terminated, but must be at least as long as
+ the specified len.
+
+ @param len
+ the length of the string.
+
+ @return
+ a hash code for the given string.
+ */
+SAL_DLLPUBLIC sal_uInt64 SAL_CALL rtl_str_hashCode64_WithLength(
+ const sal_Char * str, sal_Int32 len ) SAL_THROW_EXTERN_C();
+
/** Search for the first occurrence of a character within a string.
The string must be null-terminated.
diff --git a/include/rtl/string.hxx b/include/rtl/string.hxx
index fb7283b..24bb980 100644
--- a/include/rtl/string.hxx
+++ b/include/rtl/string.hxx
@@ -892,6 +892,19 @@ public:
}
/**
+ Returns a 64bit hash of the string data.
+ This hashes the entire data, while hashCode would do sampling for larger
string sizes.
+
+ @return a hash code value of the string data
+
+ @see hashCode() for simple hashes
+ */
+ sal_uInt64 hashCode64() const SAL_THROW(())
+ {
+ return rtl_str_hashCode64_WithLength( pData->buffer, pData->length );
+ }
+
+ /**
Returns a hashcode for this string.
@return a hash code value for this object.
diff --git a/include/rtl/ustring.h b/include/rtl/ustring.h
index 80c6bcc..2069899 100644
--- a/include/rtl/ustring.h
+++ b/include/rtl/ustring.h
@@ -551,6 +551,24 @@ SAL_DLLPUBLIC sal_Int32 SAL_CALL rtl_ustr_hashCode(
SAL_DLLPUBLIC sal_Int32 SAL_CALL rtl_ustr_hashCode_WithLength(
const sal_Unicode * str, sal_Int32 len ) SAL_THROW_EXTERN_C();
+/** Return a hash code (64bit) for a string.
+
+ It is not allowed to store the hash code persistently, because later
+ versions could return other hash codes.
+
+ @param str
+ a string. Need not be null-terminated, but must be at least as long as
+ the specified len.
+
+ @param len
+ the length of the string.
+
+ @return
+ a hash code for the given string.
+ */
+SAL_DLLPUBLIC sal_uInt64 SAL_CALL rtl_ustr_hashCode64_WithLength(
+ const sal_Unicode * str, sal_Int32 len ) SAL_THROW_EXTERN_C();
+
/** Search for the first occurrence of a character within a string.
The string must be null-terminated.
diff --git a/sal/rtl/strtmpl.cxx b/sal/rtl/strtmpl.cxx
index fc618d3..f2eac10 100644
--- a/sal/rtl/strtmpl.cxx
+++ b/sal/rtl/strtmpl.cxx
@@ -252,6 +252,19 @@ sal_Int32 SAL_CALL IMPL_RTL_STRNAME( hashCode )( const
IMPL_RTL_STRCODE* pStr )
/* ----------------------------------------------------------------------- */
+sal_uInt64 SAL_CALL IMPL_RTL_STRNAME( hashCode64_WithLength )( const
IMPL_RTL_STRCODE* pStr,
+ sal_Int32 nLen )
+ SAL_THROW_EXTERN_C()
+{
+ sal_uInt64 nHash = 0;
+
+ for( sal_Int32 i = 0; i < nLen; i++ )
+ nHash = (nHash << 5) - nHash + *pStr++;
+ return nHash;
+}
+
+/* ----------------------------------------------------------------------- */
+
sal_Int32 SAL_CALL IMPL_RTL_STRNAME( hashCode_WithLength )( const
IMPL_RTL_STRCODE* pStr,
sal_Int32 nLen )
SAL_THROW_EXTERN_C()
diff --git a/sal/util/sal.map b/sal/util/sal.map
index 1456d6d..470da31 100644
--- a/sal/util/sal.map
+++ b/sal/util/sal.map
@@ -221,6 +221,7 @@ UDK_3_0_0 {
rtl_str_shortenedCompareIgnoreAsciiCase_WithLength;
rtl_str_hashCode;
rtl_str_hashCode_WithLength;
+ rtl_str_hashCode64_WithLength;
rtl_str_indexOfChar;
rtl_str_indexOfChar_WithLength;
rtl_str_indexOfStr;
diff --git a/sd/source/core/sdpage2.cxx b/sd/source/core/sdpage2.cxx
index 0f7f7cf..a870895 100644
--- a/sd/source/core/sdpage2.cxx
+++ b/sd/source/core/sdpage2.cxx
@@ -54,16 +54,6 @@ using namespace ::com::sun::star::office;
extern void NotifyDocumentEvent( SdDrawDocument* pDocument, const OUString& rEventName,
const Reference< XInterface >& xSource );
-static sal_uInt64 lcl_getHash( OString aString )
-{
- sal_Int32 len = aString.getLength();
- sal_uInt64 nHash = 0;
-
- for( sal_Int32 i = 0; i < len; i++ )
- nHash = (nHash << 5) - nHash + aString[i];
- return nHash;
-}
-
/*************************************************************************
|*
|* Sets: names of layout, master page links and templates for presentation
@@ -615,7 +605,7 @@ OString SdPage::stringify() const
sal_uInt64 SdPage::getHash() const
{
- return lcl_getHash( stringify() );
+ return stringify().hashCode64();
}
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