Initial version of raster GeoTIFF workflow

oss-internship-2020/gdal/CMakeLists.txt

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+cmake_minimum_required(VERSION 3.10) 
+
+project(test CXX C)
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED True)
+
+set(SAPI_ROOT "/usr/local/google/home/inach/work/sandboxed-api" CACHE PATH "Path to the Sandboxed API source tree")
+#   cmake .. -G Ninja -DSAPI_ROOT=$HOME/sapi_root
+
+set(SAPI_ENABLE_EXAMPLES OFF CACHE BOOL "")
+set(SAPI_ENABLE_TESTS OFF CACHE BOOL "")
+add_subdirectory("${SAPI_ROOT}"
+                 "${CMAKE_BINARY_DIR}/sandboxed-api-build"
+                 # Omit this to have the full Sandboxed API in IDE
+                 EXCLUDE_FROM_ALL)
+
+add_library(libgdal STATIC IMPORTED)
+set_property(TARGET libgdal PROPERTY IMPORTED_LOCATION "${CMAKE_CURRENT_SOURCE_DIR}/lib/libgdal.a")
+               
+find_package(PNG REQUIRED)
+
+target_link_libraries(libgdal INTERFACE
+    crypto expat jpeg 
+    /usr/lib/x86_64-linux-gnu/libproj.so
+    /usr/lib/x86_64-linux-gnu/libpcre.so
+    sqlite3 tiff z pthread m rt dl curl
+    PNG::PNG)
+
+add_sapi_library(gdal_sapi
+    FUNCTIONS GDALOpen GDALAllRegister GDALGetDatasetDriver 
+        GDALGetDriverShortName GDALGetDriverLongName GDALGetRasterXSize 
+        GDALGetRasterYSize GDALGetRasterCount GDALGetProjectionRef
+        GDALOpenEx  GDALGetGeoTransform GDALGetRasterBand GDALGetBlockSize
+        GDALGetRasterMinimum GDALGetRasterMaximum GDALGetRasterBandXSize
+        GDALGetRasterBandYSize GDALRasterIO
+    
+    INPUTS "/usr/include/gdal/gdal.h" 
+    LIBRARY libgdal
+    LIBRARY_NAME gdal
+    
+    NAMESPACE ""
+)
+
+target_include_directories(gdal_sapi INTERFACE
+    "${PROJECT_BINARY_DIR}"
+)
+
+add_executable(raster
+    raster.cc
+)
+
+target_link_libraries(raster
+    gdal_sapi
+    sapi::sapi    
+)

oss-internship-2020/gdal/README.md

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+# GDAL Raster GeoTIFF Workflow
+
+```
+Build Tools: CMake/Ninja
+OS: Linux
+```
+
+### For testing: 
+`mkdir build && cd build`
+
+`cmake .. -G Ninja`
+
+`ninja`
+
+`./raster` 
+
+## About the project
+    GDAL is a translator library for raster and vector 
+    geospatial data format. 
+    The project consist in rastering a GeoTIFF file format 
+    using GDAL functionalities and sandboxed methods. 
+
+## Implementation
+    
+*Sandboxing...*
+
+    The purpose of sandboxing is to limit the permissions 
+    and capabilities of library’s methods, in order to 
+    secure the usage of them. After obtaining the sandbox, 
+    the functions will be called through an Sandbox API 
+    (being called api in the current test) and so, the 
+    operations, system calls or namspaces access may be 
+    controlled. 
+
+*Raster process...*
+
+    From gdal.h header useful methods are added to sapi 
+    library builded with CMake. 
+
+    One .tiff file is manipulated with GDALOpen 
+    functionality, which extracts a pointer to the data set
+    containg a list of raster bands, all pertaining to the
+    same area. 
+    Metadata, a coordinate system, a georeferencing
+    transform, size of raster and various other information
+    are kept into the data set that corresponds to the image.
+
+    To create an array containing the image information, the
+    dimentions needed are extracted using some specific 
+    GDAL(X/Y)Size functions applied to the block.
+    GDALRasterBand function takes care of data type conversion, one more step following: placing the
+    converted data (with RasterIO method) into the created
+    and well allocated structure.

oss-internship-2020/gdal/raster.cc

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+#include <gflags/gflags.h>
+#include <glog/logging.h>
+
+#include <iostream>
+
+#include "gdal_sapi.sapi.h"
+#include "sandboxed_api/sandbox2/util/fileops.h"
+
+class GdalSapiSandbox : public gdalSandbox {
+ public:
+  std::unique_ptr<sandbox2::Policy> ModifyPolicy(
+      sandbox2::PolicyBuilder*) override {
+    return sandbox2::PolicyBuilder()
+        .DangerDefaultAllowAll()
+        .DisableNamespaces()
+        .BuildOrDie();
+  }
+};
+
+int main() {
+  GdalSapiSandbox sandbox;
+  sandbox.Init().IgnoreError();
+  gdalApi api(&sandbox);
+
+  // Reading GDALDataset from a (local, specific) file.
+  std::string filename = "CANYrelief1-geo.tif";
+  sapi::v::CStr s(filename.data());
+
+  api.GDALAllRegister().IgnoreError();
+  auto open = api.GDALOpen(s.PtrBefore(), GDALAccess::GA_ReadOnly);
+  sapi::v::RemotePtr ptrDataset(open.value());
+
+  LOG(INFO) << "Dataset pointer adress: " << open.value() << std::endl;
+  LOG(INFO) << ptrDataset.ToString() << std::endl;
+  if (!open.value()) {
+    printf("NULL pointer for Dataset.\n");
+    return 1;
+  }
+
+  // Printing some general information about the dataset.
+  auto driver = api.GDALGetDatasetDriver(&ptrDataset);
+  sapi::v::RemotePtr ptrDriver(driver.value());
+
+  auto driverShortName = api.GDALGetDriverShortName(&ptrDriver);
+  auto driverLongName = api.GDALGetDriverLongName(&ptrDriver);
+
+  sapi::v::RemotePtr ptrDriverShortName(driverShortName.value());
+  sapi::v::RemotePtr ptrDriverLongName(driverLongName.value());
+
+  LOG(INFO) << "Driver short name: "
+            << sandbox.GetCString(ptrDriverShortName).value().c_str();
+  LOG(INFO) << "Driver long name: "
+            << sandbox.GetCString(ptrDriverLongName).value().c_str();
+
+  // Checking that GetGeoTransform is valid.
+  std::vector<double> adfGeoTransform(6);
+  sapi::v::Array<double> adfGeoTransformArray(&adfGeoTransform[0],
+                                              adfGeoTransform.size());
+
+  api.GDALGetGeoTransform(&ptrDataset, adfGeoTransformArray.PtrBoth())
+      .IgnoreError();
+
+  LOG(INFO) << "Origin = (" << adfGeoTransform[0] << ", " << adfGeoTransform[3]
+            << ")" << std::endl;
+  LOG(INFO) << "Pixel Size = (" << adfGeoTransform[0] << ", "
+            << adfGeoTransform[3] << ")" << std::endl;
+
+  std::vector<int> nBlockXSize(1);
+  std::vector<int> nBlockYSize(1);
+
+  sapi::v::Array<int> nBlockXSizeArray(&nBlockXSize[0], nBlockXSize.size());
+  sapi::v::Array<int> nBlockYSizeArray(&nBlockYSize[0], nBlockYSize.size());
+
+  auto band = api.GDALGetRasterBand(&ptrDataset, 1);
+  LOG(INFO) << "Band pointer adress: " << band.value() << std::endl;
+  if (!band.value()) {
+    printf("NULL pointer for Band.\n");
+    return 1;
+  }
+
+  sapi::v::RemotePtr ptrBand(band.value());
+  api.GDALGetBlockSize(&ptrBand, nBlockXSizeArray.PtrBoth(),
+                       nBlockYSizeArray.PtrBoth())
+      .IgnoreError();
+
+  LOG(INFO) << "Block = " << nBlockXSize[0] << " x " << nBlockYSize[0]
+            << std::endl;
+
+  std::vector<int> bGotMin(1);
+  std::vector<int> bGotMax(1);
+
+  sapi::v::Array<int> bGotMinArray(&bGotMin[0], bGotMin.size());
+  sapi::v::Array<int> bGotMaxArray(&bGotMax[0], bGotMax.size());
+
+  auto adfMin = api.GDALGetRasterMinimum(&ptrBand, bGotMinArray.PtrBoth());
+  auto adfMax = api.GDALGetRasterMaximum(&ptrBand, bGotMaxArray.PtrBoth());
+
+  auto nXSize = api.GDALGetRasterBandXSize(&ptrBand);
+  auto nYSize = api.GDALGetRasterBandYSize(&ptrBand);
+
+  std::vector<int8_t> rasterData(nXSize.value() * nYSize.value(), -1);
+  sapi::v::Array<int8_t> rasterDataArray(&rasterData[0], rasterData.size());
+
+  api.GDALRasterIO(&ptrBand, GF_Read, 0, 0, nXSize.value(), nYSize.value(),
+                   rasterDataArray.PtrBoth(), nXSize.value(), nYSize.value(),
+                   GDT_Byte, 0, 0)
+      .IgnoreError();
+
+  std::cout << "Raster data info: " << rasterDataArray.ToString() << std::endl;
+
+  // To print the data content: `std::cout << rasterDataArray.GetData() <<
+  // std::endl;`
+
+  return 0;
+}