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mdbx: shrinking memory-mapping for Windows (initial).

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Change-Id: I3c3c2df0747c788ea36d7764c1e8139098ca62be
This commit is contained in:
Leo Yuriev
2018-01-07 14:37:38 +03:00
parent f10f5b376f
commit 30bd7d3078
5 changed files with 301 additions and 67 deletions
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129
src/osal.c
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@@ -768,21 +768,15 @@ int mdbx_msync(mdbx_mmap_t *map, size_t offset, size_t length, int async) {
#endif
}
int mdbx_mmap(int flags, mdbx_mmap_t *map, size_t must, size_t limit) {
assert(must <= limit);
int mdbx_mmap(int flags, mdbx_mmap_t *map, size_t size, size_t limit) {
assert(size <= limit);
#if defined(_WIN32) || defined(_WIN64)
NTSTATUS rc;
map->length = 0;
map->current = 0;
map->section = NULL;
map->address = nullptr;
uint64_t filesize;
rc = mdbx_filesize(map->fd, &filesize);
if (rc != MDBX_SUCCESS)
return rc;
if (GetFileType(map->fd) != FILE_TYPE_DISK)
return ERROR_FILE_OFFLINE;
@@ -861,13 +855,19 @@ int mdbx_mmap(int flags, mdbx_mmap_t *map, size_t must, size_t limit) {
}
}
if (filesize > must) {
rc = mdbx_ftruncate(map->fd, must);
(void)rc /* ignore error, because Windows unable shrink mapped file */;
rc = mdbx_filesize(map->fd, &map->filesize);
if (rc != MDBX_SUCCESS)
return rc;
if ((flags & MDBX_RDONLY) == 0 && map->filesize != size) {
rc = mdbx_ftruncate(map->fd, size);
if (rc == MDBX_SUCCESS)
map->filesize = size;
/* ignore error, because Windows unable shrink file
* that already mapped (by another process) */;
}
LARGE_INTEGER SectionSize;
SectionSize.QuadPart = must;
SectionSize.QuadPart = size;
rc = NtCreateSection(
&map->section,
/* DesiredAccess */ (flags & MDBX_WRITEMAP)
@@ -878,7 +878,6 @@ int mdbx_mmap(int flags, mdbx_mmap_t *map, size_t must, size_t limit) {
/* SectionPageProtection */ (flags & MDBX_RDONLY) ? PAGE_READONLY
: PAGE_READWRITE,
/* AllocationAttributes */ SEC_RESERVE, map->fd);
if (!NT_SUCCESS(rc))
return ntstatus2errcode(rc);
@@ -892,7 +891,6 @@ int mdbx_mmap(int flags, mdbx_mmap_t *map, size_t must, size_t limit) {
/* AllocationType */ (flags & MDBX_RDONLY) ? 0 : MEM_RESERVE,
/* Win32Protect */ (flags & MDBX_WRITEMAP) ? PAGE_READWRITE
: PAGE_READONLY);
if (!NT_SUCCESS(rc)) {
NtClose(map->section);
map->section = 0;
@@ -905,7 +903,7 @@ int mdbx_mmap(int flags, mdbx_mmap_t *map, size_t must, size_t limit) {
map->length = ViewSize;
return MDBX_SUCCESS;
#else
(void)must;
(void)size;
map->address = mmap(
NULL, limit, (flags & MDBX_WRITEMAP) ? PROT_READ | PROT_WRITE : PROT_READ,
MAP_SHARED, map->fd, 0);
@@ -938,31 +936,88 @@ int mdbx_munmap(mdbx_mmap_t *map) {
return MDBX_SUCCESS;
}
int mdbx_mresize(int flags, mdbx_mmap_t *map, size_t atleast, size_t limit) {
assert(atleast <= limit);
int mdbx_mresize(int flags, mdbx_mmap_t *map, size_t size, size_t limit) {
assert(size <= limit);
assert(size != map->current || limit != map->length || size < map->filesize);
#if defined(_WIN32) || defined(_WIN64)
if (limit != map->length) {
int rc = mdbx_munmap(map);
if (rc == MDBX_SUCCESS)
rc = mdbx_mmap(flags, map, atleast, limit);
if (!(flags & MDBX_RDONLY) && limit == map->length && size > map->current) {
/* growth rw-section */
LARGE_INTEGER growth;
growth.QuadPart = size;
NTSTATUS rc = NtExtendSection(map->section, &growth);
if (NT_SUCCESS(rc))
map->filesize = map->current = size;
return ntstatus2errcode(rc);
}
/* Windows unable:
* - shrinking a mapped file;
* - change size of mapped view;
* - extend read-only mapping;
* Therefore we should unmap/map entire section. */
NTSTATUS rc = NtUnmapViewOfSection(GetCurrentProcess(), map->address);
if (!NT_SUCCESS(rc))
return ntstatus2errcode(rc);
rc = NtClose(map->section);
map->current = map->length = 0;
map->section = NULL;
if (!NT_SUCCESS(rc))
return ntstatus2errcode(rc);
rc = mdbx_filesize(map->fd, &map->filesize);
if (rc != MDBX_SUCCESS)
return rc;
if ((flags & MDBX_RDONLY) == 0 && map->filesize != size) {
rc = mdbx_ftruncate(map->fd, size);
if (rc == MDBX_SUCCESS)
map->filesize = size;
/* ignore error, because Windows unable shrink file
* that already mapped (by another process) */;
}
if (atleast > map->current) {
/* growth */
LARGE_INTEGER new_size;
new_size.QuadPart = atleast;
NTSTATUS rc = NtExtendSection(map->section, &new_size);
map->current = atleast;
if (!NT_SUCCESS(rc))
return ntstatus2errcode(rc);
LARGE_INTEGER SectionSize;
SectionSize.QuadPart = size;
rc = NtCreateSection(
&map->section,
/* DesiredAccess */ (flags & MDBX_WRITEMAP)
? SECTION_QUERY | SECTION_MAP_READ | SECTION_EXTEND_SIZE |
SECTION_MAP_WRITE
: SECTION_QUERY | SECTION_MAP_READ | SECTION_EXTEND_SIZE,
/* ObjectAttributes */ NULL,
/* MaximumSize (InitialSize) */ &SectionSize,
/* SectionPageProtection */ (flags & MDBX_RDONLY) ? PAGE_READONLY
: PAGE_READWRITE,
/* AllocationAttributes */ SEC_RESERVE, map->fd);
if (!NT_SUCCESS(rc))
return ntstatus2errcode(rc);
retry:;
SIZE_T ViewSize = (flags & MDBX_RDONLY) ? size : limit;
rc = NtMapViewOfSection(
map->section, GetCurrentProcess(), &map->address,
/* ZeroBits */ 0,
/* CommitSize */ 0,
/* SectionOffset */ NULL, &ViewSize,
/* InheritDisposition */ ViewUnmap,
/* AllocationType */ (flags & MDBX_RDONLY) ? 0 : MEM_RESERVE,
/* Win32Protect */ (flags & MDBX_WRITEMAP) ? PAGE_READWRITE
: PAGE_READONLY);
if (!NT_SUCCESS(rc)) {
if (map->address) {
map->address = NULL;
goto retry;
}
NtClose(map->section);
map->section = 0;
return ntstatus2errcode(rc);
}
if (atleast < map->current) {
/* Windows unable shrinking a mapped file */
return MDBX_RESULT_TRUE;
}
return MDBX_SUCCESS;
assert(map->address != MAP_FAILED);
map->current = (size_t)SectionSize.QuadPart;
map->length = ViewSize;
#else
(void)flags;
if (limit != map->length) {
void *ptr = mremap(map->address, map->length, limit, MREMAP_MAYMOVE);
if (ptr == MAP_FAILED)
@@ -970,8 +1025,10 @@ int mdbx_mresize(int flags, mdbx_mmap_t *map, size_t atleast, size_t limit) {
map->address = ptr;
map->length = limit;
}
return mdbx_ftruncate(map->fd, atleast);
if ((flags & MDBX_RDONLY) == 0)
return mdbx_ftruncate(map->fd, size);
#endif
return MDBX_SUCCESS;
}
/*----------------------------------------------------------------------------*/