Implement a ZipArchives.jl extension + an extension priority system!

Project.toml

@@ -10,16 +10,19 @@ GeoFormatTypes = "68eda718-8dee-11e9-39e7-89f7f65f511f"
 GeoInterface = "cf35fbd7-0cd7-5166-be24-54bfbe79505f"
 GeoInterfaceMakie = "0edc0954-3250-4c18-859d-ec71c1660c08"
 GeoInterfaceRecipes = "0329782f-3d07-4b52-b9f6-d3137cf03c7a"
+Mmap = "a63ad114-7e13-5084-954f-fe012c677804"
 OrderedCollections = "bac558e1-5e72-5ebc-8fee-abe8a469f55d"
 RecipesBase = "3cdcf5f2-1ef4-517c-9805-6587b60abb01"
 Tables = "bd369af6-aec1-5ad0-b16a-f7cc5008161c"
 
 [weakdeps]
 Makie = "ee78f7c6-11fb-53f2-987a-cfe4a2b5a57a"
+ZipArchives = "49080126-0e18-4c2a-b176-c102e4b3760c"
 ZipFile = "a5390f91-8eb1-5f08-bee0-b1d1ffed6cea"
 
 [extensions]
 ShapefileMakieExt = "Makie"
+ShapefileZipArchivesExt = "ZipArchives"
 ShapefileZipFileExt = "ZipFile"
 
 [compat]
@@ -30,15 +33,17 @@ GeoInterface = "1.0"
 GeoInterfaceMakie = "0.1"
 GeoInterfaceRecipes = "1.0"
 Makie = "0.20, 0.21, 0.22"
+Mmap = "1.11.0"
 OrderedCollections = "1"
 RecipesBase = "1"
 Tables = "0.2, 1"
+ZipArchives = "2"
 ZipFile = "0.9, 0.10"
 julia = "1.9"
 
 [extras]
-ArchGDAL = "c9ce4bd3-c3d5-55b8-8973-c0e20141b8c3"
 Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
+ArchGDAL = "c9ce4bd3-c3d5-55b8-8973-c0e20141b8c3"
 DataFrames = "a93c6f00-e57d-5684-b7b6-d8193f3e46c0"
 Makie = "ee78f7c6-11fb-53f2-987a-cfe4a2b5a57a"
 Plots = "91a5bcdd-55d7-5caf-9e0b-520d859cae80"

ext/ShapefileZipArchivesExt.jl

@@ -0,0 +1,51 @@
+module ShapefileZipArchivesExt
+import ZipArchives, Shapefile
+import Shapefile: _read_shp_from_ziparchive, _is_ziparchives_loaded
+import Mmap # to present zip files as AbstractVector{UInt8}
+
+_is_ziparchives_loaded() = true
+
+function _read_shp_from_ziparchive(zipfile)
+  zip_file_handler = open(zipfile)
+  mmapped_zip_file = Mmap.mmap(zip_file_handler)
+  r = ZipArchives.ZipReader(mmapped_zip_file)
+  # need to get dbx
+  shpdata, shxdata, dbfdata, prjdata = nothing, nothing, nothing, nothing
+  for filename in ZipArchives.zip_names(r)
+    lfn = lowercase(filename)
+    if endswith(lfn, ".shp")
+      shpdata = IOBuffer(ZipArchives.zip_readentry(r, filename))
+    elseif endswith(lfn, ".shx")
+      shxdata = ZipArchives.zip_readentry(r, filename, Shapefile.IndexHandle)
+    elseif endswith(lfn, ".dbf")
+      ZipArchives.zip_openentry(r, filename) do io
+        dbfdata = Shapefile.DBFTables.Table(io)
+      end
+    elseif endswith(lfn, "prj")
+      prjdata = try
+        Shapefile.GeoFormatTypes.ESRIWellKnownText(Shapefile.GeoFormatTypes.CRS(), ZipArchives.zip_readentry(r, filename, String))
+      catch
+        @warn "Projection file $zipfile/$lfn appears to be corrupted. `nothing` used for `crs`"
+        nothing 
+      end
+    end
+  end
+
+  # Finished the reading loop, we don't need the zip file anymore.
+
+  close(zip_file_handler)
+
+  # Populate the Shapefile.Table
+  @assert shpdata !== nothing
+  shp = if shxdata !== nothing # we have shxdata/index 
+    read(shpdata, Shapefile.Handle, shxdata)
+  else
+    read(shpdata, Shapefile.Handle)
+  end 
+  if prjdata !== nothing
+    shp.crs = prjdata 
+  end 
+  return Shapefile.Table(shp, dbfdata)
+end 
+
+end

ext/ShapefileZipFileExt.jl

@@ -1,6 +1,9 @@
 module ShapefileZipFileExt
 import ZipFile, Shapefile
-import Shapefile: _read_shp_from_zipfile
+import Shapefile: _read_shp_from_zipfile, _is_zipfiles_loaded
+
+_is_zipfiles_loaded() = true
+
 function _read_shp_from_zipfile(zipfile)
   r = ZipFile.Reader(zipfile)
   # need to get dbx

src/table.jl

@@ -68,7 +68,16 @@ function Table(shp::Handle{T}, dbf::DBFTables.Table) where {T}
 end
 function Table(path::AbstractString)
     if endswith(path, ".zip")
-        return _read_shp_from_zipfile(path)
+        if _is_ziparchives_loaded()
+            return _read_shp_from_ziparchive(path)
+        elseif _is_zipfiles_loaded()
+            return _read_shp_from_zipfile(path)
+        else
+            throw(ArgumentError("""
+            ZipFile.jl or ZipArchives.jl are not loaded, so Shapefile.jl cannot read zip files.  
+            Please run `using ZipArchives` or `using ZipFile` to enable reading zip files.
+            """))
+        end
     end
     paths = _shape_paths(path)
     isfile(paths.shp) || throw(ArgumentError("File not found: $(paths.dbf)"))
@@ -84,6 +93,10 @@ function Table(path::AbstractString)
 end
 
 function _read_shp_from_zipfile end
+function _read_shp_from_ziparchive end
+
+_is_zipfiles_loaded(args...) = false # these are set to true in extensions
+_is_ziparchives_loaded(args...) = false # these are set to true in extensions
 
 getshp(t::Table) = getfield(t, :shp)
 getdbf(t::Table) = getfield(t, :dbf)