CPLErr GDALWMSRasterBand::ZeroBlock(int x, int y, int to_buffer_band, void *buffer) {
CPLErr ret = CE_None;
for (int ib = 1; ib <= m_parent_dataset->nBands; ++ib) {
if (ret == CE_None) {
void *p = NULL;
GDALRasterBlock *b = NULL;
if ((buffer != NULL) && (ib == to_buffer_band)) {
p = buffer;
} else {
GDALWMSRasterBand *band = static_cast<GDALWMSRasterBand *>(m_parent_dataset->GetRasterBand(ib));
if (m_overview >= 0) band = static_cast<GDALWMSRasterBand *>(band->GetOverview(m_overview));
if (!band->IsBlockInCache(x, y)) {
b = band->GetLockedBlockRef(x, y, true);
if (b != NULL) {
p = b->GetDataRef();
if (p == NULL) {
CPLError(CE_Failure, CPLE_AppDefined, "GDALWMS: GetDataRef returned NULL.");
ret = CE_Failure;
}
}
}
}
if (p != NULL) {
unsigned char *paby = reinterpret_cast<unsigned char *>(p);
int block_size = nBlockXSize * nBlockYSize * (GDALGetDataTypeSize(eDataType) / 8);
for (int i = 0; i < block_size; ++i) paby[i] = 0;
}
if (b != NULL) {
b->DropLock();
}
}
}
return ret;
}
CPLErr GDALWMSRasterBand::ReadBlocks(int x, int y, void *buffer, int bx0, int by0, int bx1, int by1, int advise_read) {
CPLErr ret = CE_None;
int i;
int max_request_count = (bx1 - bx0 + 1) * (by1 - by0 + 1);
int request_count = 0;
CPLHTTPRequest *download_requests = NULL;
GDALWMSCache *cache = m_parent_dataset->m_cache;
struct BlockXY {
int x, y;
} *download_blocks = NULL;
if (!m_parent_dataset->m_offline_mode) {
download_requests = new CPLHTTPRequest[max_request_count];
download_blocks = new BlockXY[max_request_count];
}
char **http_request_opts = NULL;
if (m_parent_dataset->m_http_timeout != -1) {
CPLString http_request_optstr;
http_request_optstr.Printf("TIMEOUT=%d", m_parent_dataset->m_http_timeout);
http_request_opts = CSLAddString(http_request_opts, http_request_optstr.c_str());
}
for (int iy = by0; iy <= by1; ++iy) {
for (int ix = bx0; ix <= bx1; ++ix) {
bool need_this_block = false;
if (!advise_read) {
for (int ib = 1; ib <= m_parent_dataset->nBands; ++ib) {
if ((ix == x) && (iy == y) && (ib == nBand)) {
need_this_block = true;
} else {
GDALWMSRasterBand *band = static_cast<GDALWMSRasterBand *>(m_parent_dataset->GetRasterBand(ib));
if (m_overview >= 0) band = static_cast<GDALWMSRasterBand *>(band->GetOverview(m_overview));
if (!band->IsBlockInCache(ix, iy)) need_this_block = true;
}
}
} else {
need_this_block = true;
}
CPLString url;
if (need_this_block) {
CPLString file_name;
AskMiniDriverForBlock(&url, ix, iy);
if ((cache != NULL) && (cache->Read(url.c_str(), &file_name) == CE_None)) {
if (advise_read) {
need_this_block = false;
} else {
void *p = 0;
if ((ix == x) && (iy == y)) p = buffer;
if (ReadBlockFromFile(ix, iy, file_name.c_str(), nBand, p, 0) == CE_None) need_this_block = false;
}
}
}
if (need_this_block) {
if (m_parent_dataset->m_offline_mode) {
if (!advise_read) {
void *p = 0;
if ((ix == x) && (iy == y)) p = buffer;
if (ZeroBlock(ix, iy, nBand, p) != CE_None) {
CPLError(CE_Failure, CPLE_AppDefined, "GDALWMS: ZeroBlock failed.");
ret = CE_Failure;
}
}
} else {
CPLHTTPInitializeRequest(&download_requests[request_count], url.c_str(), http_request_opts);
download_blocks[request_count].x = ix;
download_blocks[request_count].y = iy;
++request_count;
}
}
}
}
if (http_request_opts != NULL) {
CSLDestroy(http_request_opts);
}
if (request_count > 0) {
char **opts = NULL;
CPLString optstr;
if (m_parent_dataset->m_http_max_conn != -1) {
optstr.Printf("MAXCONN=%d", m_parent_dataset->m_http_max_conn);
opts = CSLAddString(opts, optstr.c_str());
}
if (CPLHTTPFetchMulti(download_requests, request_count, opts) != CE_None) {
CPLError(CE_Failure, CPLE_AppDefined, "GDALWMS: CPLHTTPFetchMulti failed.");
ret = CE_Failure;
}
if (opts != NULL) {
CSLDestroy(opts);
}
}
for (i = 0; i < request_count; ++i) {
if (ret == CE_None) {
if ((download_requests[i].nStatus == 200) && (download_requests[i].pabyData != NULL) && (download_requests[i].nDataLen > 0)) {
CPLString file_name(BufferToVSIFile(download_requests[i].pabyData, download_requests[i].nDataLen));
if (file_name.size() > 0) {
/* check for error xml */
if (download_requests[i].nDataLen >= 20) {
const char *download_data = reinterpret_cast<char *>(download_requests[i].pabyData);
if (EQUALN(download_data, "<?xml ", 6)
|| EQUALN(download_data, "<!DOCTYPE ", 10)
|| EQUALN(download_data, "<ServiceException", 17)) {
if (ReportWMSException(file_name.c_str()) != CE_None) {
CPLError(CE_Failure, CPLE_AppDefined, "GDALWMS: The server returned unknown exception.");
}
ret = CE_Failure;
}
}
if (ret == CE_None) {
if (advise_read && !m_parent_dataset->m_verify_advise_read) {
if (cache != NULL) {
cache->Write(download_requests[i].pszURL, file_name);
}
} else {
void *p = 0;
if ((download_blocks[i].x == x) && (download_blocks[i].y == y)) p = buffer;
if (ReadBlockFromFile(download_blocks[i].x, download_blocks[i].y, file_name.c_str(), nBand, p, advise_read) == CE_None) {
if (cache != NULL) {
cache->Write(download_requests[i].pszURL, file_name);
}
} else {
CPLError(CE_Failure, CPLE_AppDefined, "GDALWMS: ReadBlockFromFile (%s) failed.",
download_requests[i].pszURL);
ret = CE_Failure;
}
}
}
VSIUnlink(file_name.c_str());
}
} else if (download_requests[i].nStatus == 204) {
if (!advise_read) {
void *p = 0;
if ((download_blocks[i].x == x) && (download_blocks[i].y == y)) p = buffer;
if (ZeroBlock(download_blocks[i].x, download_blocks[i].y, nBand, p) != CE_None) {
CPLError(CE_Failure, CPLE_AppDefined, "GDALWMS: ZeroBlock failed.");
ret = CE_Failure;
}
}
} else {
CPLError(CE_Failure, CPLE_AppDefined, "GDALWMS: Unable to download block %d, %d.\n URL: %s\n HTTP status code: %d, error: %s.",
download_blocks[i].x, download_blocks[i].y, download_requests[i].pszURL, download_requests[i].nStatus,
download_requests[i].pszError ? download_requests[i].pszError : "(null)");
ret = CE_Failure;
}
}
CPLHTTPCleanupRequest(&download_requests[i]);
}
if (!m_parent_dataset->m_offline_mode) {
delete[] download_blocks;
delete[] download_requests;
}
return ret;
}
CPLErr GDALWMSRasterBand::ReadBlockFromFile(int x, int y, const char *file_name, int to_buffer_band, void *buffer, int advise_read) {
CPLErr ret = CE_None;
GDALDataset *ds = 0;
GByte *color_table = NULL;
int i;
//CPLDebug("WMS", "ReadBlockFromFile: to_buffer_band=%d, (x,y)=(%d, %d)", to_buffer_band, x, y);
/* expected size */
const int esx = MIN(MAX(0, (x + 1) * nBlockXSize), nRasterXSize) - MIN(MAX(0, x * nBlockXSize), nRasterXSize);
const int esy = MIN(MAX(0, (y + 1) * nBlockYSize), nRasterYSize) - MIN(MAX(0, y * nBlockYSize), nRasterYSize);
ds = reinterpret_cast<GDALDataset*>(GDALOpen(file_name, GA_ReadOnly));
if (ds != NULL) {
int sx = ds->GetRasterXSize();
int sy = ds->GetRasterYSize();
bool accepted_as_no_alpha = false; // if the request is for 4 bands but the wms returns 3
/* Allow bigger than expected so pre-tiled constant size images work on corners */
if ((sx > nBlockXSize) || (sy > nBlockYSize) || (sx < esx) || (sy < esy)) {
CPLError(CE_Failure, CPLE_AppDefined, "GDALWMS: Incorrect size %d x %d of downloaded block, expected %d x %d, max %d x %d.",
sx, sy, esx, esy, nBlockXSize, nBlockYSize);
ret = CE_Failure;
}
if (ret == CE_None) {
int nDSRasterCount = ds->GetRasterCount();
if (nDSRasterCount != m_parent_dataset->nBands) {
/* Maybe its an image with color table */
bool accepted_as_ct = false;
if ((eDataType == GDT_Byte) && (ds->GetRasterCount() == 1)) {
GDALRasterBand *rb = ds->GetRasterBand(1);
if (rb->GetRasterDataType() == GDT_Byte) {
GDALColorTable *ct = rb->GetColorTable();
if (ct != NULL) {
accepted_as_ct = true;
if (!advise_read) {
color_table = new GByte[256 * 4];
const int count = MIN(256, ct->GetColorEntryCount());
for (i = 0; i < count; ++i) {
GDALColorEntry ce;
ct->GetColorEntryAsRGB(i, &ce);
color_table[i] = static_cast<GByte>(ce.c1);
color_table[i + 256] = static_cast<GByte>(ce.c2);
color_table[i + 512] = static_cast<GByte>(ce.c3);
color_table[i + 768] = static_cast<GByte>(ce.c4);
}
for (i = count; i < 256; ++i) {
color_table[i] = 0;
color_table[i + 256] = 0;
color_table[i + 512] = 0;
color_table[i + 768] = 0;
}
}
}
}
}
if (nDSRasterCount == 4 && m_parent_dataset->nBands == 3)
{
/* metacarta TMS service sometimes return a 4 band PNG instead of the expected 3 band... */
}
else if (!accepted_as_ct) {
if (ds->GetRasterCount()==3 && m_parent_dataset->nBands == 4 && (eDataType == GDT_Byte))
{ // WMS returned a file with no alpha so we will fill the alpha band with "opaque"
accepted_as_no_alpha = true;
}
else
{
CPLError(CE_Failure, CPLE_AppDefined, "GDALWMS: Incorrect bands count %d in downloaded block, expected %d.",
nDSRasterCount, m_parent_dataset->nBands);
ret = CE_Failure;
}
}
}
}
if (!advise_read) {
for (int ib = 1; ib <= m_parent_dataset->nBands; ++ib) {
if (ret == CE_None) {
void *p = NULL;
GDALRasterBlock *b = NULL;
if ((buffer != NULL) && (ib == to_buffer_band)) {
p = buffer;
} else {
GDALWMSRasterBand *band = static_cast<GDALWMSRasterBand *>(m_parent_dataset->GetRasterBand(ib));
if (m_overview >= 0) band = static_cast<GDALWMSRasterBand *>(band->GetOverview(m_overview));
if (!band->IsBlockInCache(x, y)) {
b = band->GetLockedBlockRef(x, y, true);
if (b != NULL) {
p = b->GetDataRef();
if (p == NULL) {
CPLError(CE_Failure, CPLE_AppDefined, "GDALWMS: GetDataRef returned NULL.");
ret = CE_Failure;
}
}
}
else
{
//CPLDebug("WMS", "Band %d, block (x,y)=(%d, %d) already in cache", band->GetBand(), x, y);
}
}
if (p != NULL) {
int pixel_space = GDALGetDataTypeSize(eDataType) / 8;
int line_space = pixel_space * nBlockXSize;
if (color_table == NULL) {
if( ib <= ds->GetRasterCount()) {
if (ds->RasterIO(GF_Read, 0, 0, sx, sy, p, sx, sy, eDataType, 1, &ib, pixel_space, line_space, 0) != CE_None) {
CPLError(CE_Failure, CPLE_AppDefined, "GDALWMS: RasterIO failed on downloaded block.");
ret = CE_Failure;
}
}
else
{ // parent expects 4 bands but file only has 3 so generate a all "opaque" 4th band
if (accepted_as_no_alpha)
{
// the file had 3 bands and we are reading band 4 (Alpha) so fill with 255 (no alpha)
GByte *byte_buffer = reinterpret_cast<GByte *>(p);
for (int y = 0; y < sy; ++y) {
for (int x = 0; x < sx; ++x) {
const int offset = x + y * line_space;
byte_buffer[offset] = 255; // fill with opaque
}
}
}
else
{ // we should never get here because this case was caught above
CPLError(CE_Failure, CPLE_AppDefined, "GDALWMS: Incorrect bands count %d in downloaded block, expected %d.",
ds->GetRasterCount(), m_parent_dataset->nBands);
ret = CE_Failure;
}
}
} else if (ib <= 4) {
if (ds->RasterIO(GF_Read, 0, 0, sx, sy, p, sx, sy, eDataType, 1, NULL, pixel_space, line_space, 0) != CE_None) {
CPLError(CE_Failure, CPLE_AppDefined, "GDALWMS: RasterIO failed on downloaded block.");
ret = CE_Failure;
}
if (ret == CE_None) {
GByte *band_color_table = color_table + 256 * (ib - 1);
GByte *byte_buffer = reinterpret_cast<GByte *>(p);
for (int y = 0; y < sy; ++y) {
for (int x = 0; x < sx; ++x) {
const int offset = x + y * line_space;
byte_buffer[offset] = band_color_table[byte_buffer[offset]];
}
}
}
} else {
CPLError(CE_Failure, CPLE_AppDefined, "GDALWMS: Color table supports at most 4 components.");
ret = CE_Failure;
}
}
if (b != NULL) {
b->DropLock();
}
}
}
}
GDALClose(ds);
} else {
CPLError(CE_Failure, CPLE_AppDefined, "GDALWMS: Unable to open downloaded block.");
ret = CE_Failure;
}
if (color_table != NULL) {
delete[] color_table;
}
return ret;
}