Merge pull request #11081 from OSGeo/backport-11026-to-release/3.10

[Backport release/3.10] Zarr: Create(): remove created files / directories if an error occurs

autotest/gdrivers/zarr_driver.py

@@ -16,6 +16,7 @@
 import base64
 import json
 import math
+import os
 import struct
 import sys
 
@@ -5532,7 +5533,7 @@ def test_zarr_read_cf1_zarrv3():
 @gdaltest.enable_exceptions()
 def test_zarr_write_partial_blocks_compressed(tmp_vsimem):
 
-    out_filename = "/vsimem/test.zarr"
+    out_filename = str(tmp_vsimem / "test.zarr")
     src_ds = gdal.Open("data/small_world.tif")
     gdal.Translate(
         out_filename,
@@ -5541,3 +5542,45 @@ def test_zarr_write_partial_blocks_compressed(tmp_vsimem):
     )
     out_ds = gdal.Open(out_filename)
     assert out_ds.ReadRaster() == src_ds.ReadRaster()
+
+
+###############################################################################
+# Test bug fix for https://github.com/OSGeo/gdal/issues/11023
+
+
+@gdaltest.enable_exceptions()
+@pytest.mark.parametrize("format", ["ZARR_V2", "ZARR_V3"])
+def test_zarr_write_cleanup_create_dir_if_bad_blocksize(tmp_path, format):
+
+    out_dirname = str(tmp_path / "test.zarr")
+    with pytest.raises(Exception):
+        gdal.Translate(
+            out_dirname,
+            "data/byte.tif",
+            options=f"-of ZARR -co FORMAT={format} -co BLOCKSIZE=1,20,20",
+        )
+    assert not os.path.exists(out_dirname)
+
+
+###############################################################################
+# Test bug fix for https://github.com/OSGeo/gdal/issues/11023
+
+
+@gdaltest.enable_exceptions()
+@pytest.mark.parametrize("format", ["ZARR_V2", "ZARR_V3"])
+def test_zarr_write_cleanup_create_dir_if_bad_blocksize_append_subdataset(
+    tmp_path, format
+):
+
+    out_dirname = str(tmp_path / "test.zarr")
+    gdal.Translate(out_dirname, "data/byte.tif", format="ZARR")
+    assert os.path.exists(out_dirname)
+    with pytest.raises(Exception):
+        gdal.Translate(
+            out_dirname,
+            "data/utm.tif",
+            options=f"-of ZARR -co APPEND_SUBDATASET=YES -co FORMAT={format} -co ARRAY_NAME=other -co BLOCKSIZE=1,20,20",
+        )
+    assert os.path.exists(out_dirname)
+    ds = gdal.Open(out_dirname)
+    assert ds.GetRasterBand(1).Checksum() == 4672

frmts/zarr/zarrdriver.cpp

@@ -996,6 +996,10 @@ GDALDataset *ZarrDataset::Create(const char *pszName, int nXSize, int nYSize,
                                  int nBandsIn, GDALDataType eType,
                                  char **papszOptions)
 {
+    // To avoid any issue with short-lived string that would be passed to us
+    const std::string osName = pszName;
+    pszName = osName.c_str();
+
     if (nBandsIn <= 0 || nXSize <= 0 || nYSize <= 0)
     {
         CPLError(CE_Failure, CPLE_NotSupported,
@@ -1028,6 +1032,22 @@ GDALDataset *ZarrDataset::Create(const char *pszName, int nXSize, int nYSize,
     }
     else
     {
+        VSIStatBufL sStat;
+        const bool bExists = VSIStatL(pszName, &sStat) == 0;
+        const bool bIsFile = bExists && !VSI_ISDIR(sStat.st_mode);
+        const bool bIsDirectory =
+            !bIsFile && ((bExists && VSI_ISDIR(sStat.st_mode)) ||
+                         !CPLStringList(VSIReadDirEx(pszName, 1)).empty());
+        if (bIsFile || bIsDirectory || bExists)
+        {
+            CPLError(CE_Failure, CPLE_FileIO, "%s %s already exists.",
+                     bIsFile        ? "File"
+                     : bIsDirectory ? "Directory"
+                                    : "Object",
+                     pszName);
+            return nullptr;
+        }
+
         const char *pszFormat =
             CSLFetchNameValueDef(papszOptions, "FORMAT", "ZARR_V2");
         auto poSharedResource =
@@ -1059,6 +1079,50 @@ GDALDataset *ZarrDataset::Create(const char *pszName, int nXSize, int nYSize,
     poDS->nRasterXSize = nXSize;
     poDS->eAccess = GA_Update;
 
+    const auto CleanupCreatedFiles =
+        [bAppendSubDS, pszName, pszArrayName, &poRG, &poDS]()
+    {
+        // Make sure all objects are released so that ZarrSharedResource
+        // is finalized and all files are serialized.
+        poRG.reset();
+        poDS.reset();
+
+        if (bAppendSubDS)
+        {
+            VSIRmdir(CPLFormFilename(pszName, pszArrayName, nullptr));
+        }
+        else
+        {
+            // Be a bit careful before wiping too much stuff...
+            // At most 5 files expected for ZARR_V2: .zgroup, .zmetadata,
+            // one (empty) subdir, . and ..
+            // and for ZARR_V3: zarr.json, one (empty) subdir, . and ..
+            const CPLStringList aosFiles(VSIReadDirEx(pszName, 6));
+            if (aosFiles.size() < 6)
+            {
+                for (const char *pszFile : aosFiles)
+                {
+                    if (pszArrayName && strcmp(pszFile, pszArrayName) == 0)
+                    {
+                        VSIRmdir(CPLFormFilename(pszName, pszFile, nullptr));
+                    }
+                    else if (!pszArrayName &&
+                             strcmp(pszFile, CPLGetBasename(pszName)) == 0)
+                    {
+                        VSIRmdir(CPLFormFilename(pszName, pszFile, nullptr));
+                    }
+                    else if (strcmp(pszFile, ".zgroup") == 0 ||
+                             strcmp(pszFile, ".zmetadata") == 0 ||
+                             strcmp(pszFile, "zarr.json") == 0)
+                    {
+                        VSIUnlink(CPLFormFilename(pszName, pszFile, nullptr));
+                    }
+                }
+                VSIRmdir(pszName);
+            }
+        }
+    };
+
     if (bAppendSubDS)
     {
         auto aoDims = poRG->GetDimensions();
@@ -1096,7 +1160,10 @@ GDALDataset *ZarrDataset::Create(const char *pszName, int nXSize, int nYSize,
             poRG->CreateDimension("X", std::string(), std::string(), nXSize);
     }
     if (poDS->m_poDimY == nullptr || poDS->m_poDimX == nullptr)
+    {
+        CleanupCreatedFiles();
         return nullptr;
+    }
 
     const bool bSingleArray =
         CPLTestBool(CSLFetchNameValueDef(papszOptions, "SINGLE_ARRAY", "YES"));
@@ -1123,7 +1190,10 @@ GDALDataset *ZarrDataset::Create(const char *pszName, int nXSize, int nYSize,
             pszNonNullArrayName, apoDims, GDALExtendedDataType::Create(eType),
             papszOptions);
         if (!poDS->m_poSingleArray)
+        {
+            CleanupCreatedFiles();
             return nullptr;
+        }
         poDS->SetMetadataItem("INTERLEAVE", bBandInterleave ? "BAND" : "PIXEL",
                               "IMAGE_STRUCTURE");
         for (int i = 0; i < nBandsIn; i++)
@@ -1145,7 +1215,10 @@ GDALDataset *ZarrDataset::Create(const char *pszName, int nXSize, int nYSize,
                                : CPLSPrintf("Band%d", i + 1),
                 apoDims, GDALExtendedDataType::Create(eType), papszOptions);
             if (poArray == nullptr)
+            {
+                CleanupCreatedFiles();
                 return nullptr;
+            }
             poDS->SetBand(i + 1, new ZarrRasterBand(poArray));
         }
     }