/src/gdal/ogr/ogrsf_frmts/jsonfg/ogrjsonfgstreamedlayer.cpp

Source
/******************************************************************************
 *
 * Project:  OpenGIS Simple Features Reference Implementation
 * Purpose:  Implementation of OGC Features and Geometries JSON (JSON-FG)
 * Author:   Even Rouault <even.rouault at spatialys.com>
 *
 ******************************************************************************
 * Copyright (c) 2023, Even Rouault <even.rouault at spatialys.com>
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#include "ogr_jsonfg.h"

/************************************************************************/
/*           OGRJSONFGStreamedLayer::OGRJSONFGStreamedLayer()           */
/************************************************************************/

OGRJSONFGStreamedLayer::OGRJSONFGStreamedLayer(GDALDataset *poDS,
                                               const char *pszName,
                                               OGRSpatialReference *poSRS,
                                               OGRwkbGeometryType eGType)
    : m_poDS(poDS), poFeatureDefn_(new OGRFeatureDefn(pszName))
{

    poFeatureDefn_->Reference();

    SetDescription(poFeatureDefn_->GetName());
    poFeatureDefn_->SetGeomType(eGType);

    if (eGType != wkbNone && poSRS != nullptr)
    {
        OGRSpatialReference *poSRSClone = poSRS->Clone();
        poFeatureDefn_->GetGeomFieldDefn(0)->SetSpatialRef(poSRSClone);
        poSRSClone->Release();
    }

    poFeatureDefn_->Seal(/* bSealFields = */ true);
}

/************************************************************************/
/*          OGRJSONFGStreamedLayer::~OGRJSONFGStreamedLayer()           */
/************************************************************************/

OGRJSONFGStreamedLayer::~OGRJSONFGStreamedLayer()
{
    poFeatureDefn_->Release();
}

/************************************************************************/
/*                              SetFile()                               */
/************************************************************************/

void OGRJSONFGStreamedLayer::SetFile(VSIVirtualHandleUniquePtr &&poFile)
{
    poFile_ = std::move(poFile);
    poFile_->Seek(0, SEEK_SET);
}

/************************************************************************/
/*                         SetStreamingParser()                         */
/************************************************************************/

void OGRJSONFGStreamedLayer::SetStreamingParser(
    std::unique_ptr<OGRJSONFGStreamingParser> &&poStreamingParser)
{
    poStreamingParser_ = std::move(poStreamingParser);
    poStreamingParser_->SetRequestedLayer(GetName());
}

/************************************************************************/
/*                            ResetReading()                            */
/************************************************************************/

void OGRJSONFGStreamedLayer::ResetReading()
{
    CPLAssert(poFile_);
    CPLAssert(poStreamingParser_);
    poStreamingParser_ = poStreamingParser_->Clone();
    poFile_->Seek(0, SEEK_SET);
    oSetUsedFIDs_.clear();
}

/************************************************************************/
/*                          EnsureUniqueFID()                           */
/************************************************************************/

OGRFeature *OGRJSONFGStreamedLayer::EnsureUniqueFID(OGRFeature *poFeat)
{
    GIntBig nFID = poFeat->GetFID();
    if (nFID == OGRNullFID)
    {
        nFID = static_cast<GIntBig>(oSetUsedFIDs_.size());
        while (oSetUsedFIDs_.find(nFID) != oSetUsedFIDs_.end())
        {
            ++nFID;
        }
    }
    else if (oSetUsedFIDs_.find(nFID) != oSetUsedFIDs_.end())
    {
        if (!bOriginalIdModified_)
        {
            CPLError(CE_Warning, CPLE_AppDefined,
                     "Several features with id = " CPL_FRMT_GIB " have "
                     "been found. Altering it to be unique. "
                     "This warning will not be emitted anymore for "
                     "this layer",
                     nFID);
            bOriginalIdModified_ = true;
        }
        nFID = static_cast<GIntBig>(oSetUsedFIDs_.size());
        while (oSetUsedFIDs_.find(nFID) != oSetUsedFIDs_.end())
        {
            ++nFID;
        }
    }
    oSetUsedFIDs_.insert(nFID);
    poFeat->SetFID(nFID);
    return poFeat;
}

/************************************************************************/
/*                         GetNextRawFeature()                          */
/************************************************************************/

OGRFeature *OGRJSONFGStreamedLayer::GetNextRawFeature()
{
    CPLAssert(poFile_);
    CPLAssert(poStreamingParser_);

    auto poFeatAndLayer = poStreamingParser_->GetNextFeature();
    if (poFeatAndLayer.first)
    {
        return EnsureUniqueFID(poFeatAndLayer.first.release());
    }

    std::vector<GByte> abyBuffer;
    abyBuffer.resize(4096 * 10);
    while (true)
    {
        size_t nRead = poFile_->Read(abyBuffer.data(), 1, abyBuffer.size());
        const bool bFinished = nRead < abyBuffer.size();
        if (!poStreamingParser_->Parse(
                std::string_view(
                    reinterpret_cast<const char *>(abyBuffer.data()), nRead),
                bFinished) ||
            poStreamingParser_->ExceptionOccurred())
        {
            break;
        }

        poFeatAndLayer = poStreamingParser_->GetNextFeature();
        if (poFeatAndLayer.first)
        {
            return EnsureUniqueFID(poFeatAndLayer.first.release());
        }
        if (bFinished)
            break;
    }

    return nullptr;
}

/************************************************************************/
/*                           TestCapability()                           */
/************************************************************************/

int OGRJSONFGStreamedLayer::TestCapability(const char *pszCap) const

{
    if (EQUAL(pszCap, OLCFastFeatureCount))
        return !m_poFilterGeom && !m_poAttrQuery && nFeatureCount_ >= 0;

    else if (EQUAL(pszCap, OLCStringsAsUTF8))
        return TRUE;

    else if (EQUAL(pszCap, OLCZGeometries) ||
             EQUAL(pszCap, OLCMeasuredGeometries) ||
             EQUAL(pszCap, OLCCurveGeometries))
    {
        return TRUE;
    }

    return FALSE;
}

/************************************************************************/
/*                          GetFeatureCount()                           */
/************************************************************************/

GIntBig OGRJSONFGStreamedLayer::GetFeatureCount(int bForce)
{
    if (!m_poFilterGeom && !m_poAttrQuery && nFeatureCount_ >= 0)
        return nFeatureCount_;
    return OGRLayer::GetFeatureCount(bForce);
}

Line	Count	Source
1		/******************************************************************************
2		*
3		* Project: OpenGIS Simple Features Reference Implementation
4		* Purpose: Implementation of OGC Features and Geometries JSON (JSON-FG)
5		* Author: Even Rouault <even.rouault at spatialys.com>
6		*
7		******************************************************************************
8		* Copyright (c) 2023, Even Rouault <even.rouault at spatialys.com>
9		*
10		* SPDX-License-Identifier: MIT
11		****************************************************************************/
12
13		#include "ogr_jsonfg.h"
14
15		/************************************************************************/
16		/* OGRJSONFGStreamedLayer::OGRJSONFGStreamedLayer() */
17		/************************************************************************/
18
19		OGRJSONFGStreamedLayer::OGRJSONFGStreamedLayer(GDALDataset *poDS,
20		const char *pszName,
21		OGRSpatialReference *poSRS,
22		OGRwkbGeometryType eGType)
23	15	: m_poDS(poDS), poFeatureDefn_(new OGRFeatureDefn(pszName))
24	15	{
25
26	15	poFeatureDefn_->Reference();
27
28	15	SetDescription(poFeatureDefn_->GetName());
29	15	poFeatureDefn_->SetGeomType(eGType);
30
31	15	if (eGType != wkbNone && poSRS != nullptr)
32	13	{
33	13	OGRSpatialReference *poSRSClone = poSRS->Clone();
34	13	poFeatureDefn_->GetGeomFieldDefn(0)->SetSpatialRef(poSRSClone);
35	13	poSRSClone->Release();
36	13	}
37
38	15	poFeatureDefn_->Seal(/* bSealFields = */ true);
39	15	}
40
41		/************************************************************************/
42		/* OGRJSONFGStreamedLayer::~OGRJSONFGStreamedLayer() */
43		/************************************************************************/
44
45		OGRJSONFGStreamedLayer::~OGRJSONFGStreamedLayer()
46	15	{
47	15	poFeatureDefn_->Release();
48	15	}
49
50		/************************************************************************/
51		/* SetFile() */
52		/************************************************************************/
53
54		void OGRJSONFGStreamedLayer::SetFile(VSIVirtualHandleUniquePtr &&poFile)
55	15	{
56	15	poFile_ = std::move(poFile);
57	15	poFile_->Seek(0, SEEK_SET);
58	15	}
59
60		/************************************************************************/
61		/* SetStreamingParser() */
62		/************************************************************************/
63
64		void OGRJSONFGStreamedLayer::SetStreamingParser(
65		std::unique_ptr<OGRJSONFGStreamingParser> &&poStreamingParser)
66	15	{
67	15	poStreamingParser_ = std::move(poStreamingParser);
68	15	poStreamingParser_->SetRequestedLayer(GetName());
69	15	}
70
71		/************************************************************************/
72		/* ResetReading() */
73		/************************************************************************/
74
75		void OGRJSONFGStreamedLayer::ResetReading()
76	0	{
77	0	CPLAssert(poFile_);
78	0	CPLAssert(poStreamingParser_);
79	0	poStreamingParser_ = poStreamingParser_->Clone();
80	0	poFile_->Seek(0, SEEK_SET);
81	0	oSetUsedFIDs_.clear();
82	0	}
83
84		/************************************************************************/
85		/* EnsureUniqueFID() */
86		/************************************************************************/
87
88		OGRFeature OGRJSONFGStreamedLayer::EnsureUniqueFID(OGRFeature poFeat)
89	28	{
90	28	GIntBig nFID = poFeat->GetFID();
91	28	if (nFID == OGRNullFID)
92	7	{
93	7	nFID = static_cast<GIntBig>(oSetUsedFIDs_.size());
94	7	while (oSetUsedFIDs_.find(nFID) != oSetUsedFIDs_.end())
95	0	{
96	0	++nFID;
97	0	}
98	7	}
99	21	else if (oSetUsedFIDs_.find(nFID) != oSetUsedFIDs_.end())
100	4	{
101	4	if (!bOriginalIdModified_)
102	4	{
103	4	CPLError(CE_Warning, CPLE_AppDefined,
104	4	"Several features with id = " CPL_FRMT_GIB " have "
105	4	"been found. Altering it to be unique. "
106	4	"This warning will not be emitted anymore for "
107	4	"this layer",
108	4	nFID);
109	4	bOriginalIdModified_ = true;
110	4	}
111	4	nFID = static_cast<GIntBig>(oSetUsedFIDs_.size());
112	7	while (oSetUsedFIDs_.find(nFID) != oSetUsedFIDs_.end())
113	3	{
114	3	++nFID;
115	3	}
116	4	}
117	28	oSetUsedFIDs_.insert(nFID);
118	28	poFeat->SetFID(nFID);
119	28	return poFeat;
120	28	}
121
122		/************************************************************************/
123		/* GetNextRawFeature() */
124		/************************************************************************/
125
126		OGRFeature *OGRJSONFGStreamedLayer::GetNextRawFeature()
127	43	{
128	43	CPLAssert(poFile_);
129	43	CPLAssert(poStreamingParser_);
130
131	43	auto poFeatAndLayer = poStreamingParser_->GetNextFeature();
132	43	if (poFeatAndLayer.first)
133	13	{
134	13	return EnsureUniqueFID(poFeatAndLayer.first.release());
135	13	}
136
137	30	std::vector<GByte> abyBuffer;
138	30	abyBuffer.resize(4096 * 10);
139	30	while (true)
140	30	{
141	30	size_t nRead = poFile_->Read(abyBuffer.data(), 1, abyBuffer.size());
142	30	const bool bFinished = nRead < abyBuffer.size();
143	30	if (!poStreamingParser_->Parse(
144	30	std::string_view(
145	30	reinterpret_cast<const char *>(abyBuffer.data()), nRead),
146	30	bFinished) \|\|
147	30	poStreamingParser_->ExceptionOccurred())
148	0	{
149	0	break;
150	0	}
151
152	30	poFeatAndLayer = poStreamingParser_->GetNextFeature();
153	30	if (poFeatAndLayer.first)
154	15	{
155	15	return EnsureUniqueFID(poFeatAndLayer.first.release());
156	15	}
157	15	if (bFinished)
158	15	break;
159	15	}
160
161	15	return nullptr;
162	30	}
163
164		/************************************************************************/
165		/* TestCapability() */
166		/************************************************************************/
167
168		int OGRJSONFGStreamedLayer::TestCapability(const char *pszCap) const
169
170	0	{
171	0	if (EQUAL(pszCap, OLCFastFeatureCount))
172	0	return !m_poFilterGeom && !m_poAttrQuery && nFeatureCount_ >= 0;
173
174	0	else if (EQUAL(pszCap, OLCStringsAsUTF8))
175	0	return TRUE;
176
177	0	else if (EQUAL(pszCap, OLCZGeometries) \|\|
178	0	EQUAL(pszCap, OLCMeasuredGeometries) \|\|
179	0	EQUAL(pszCap, OLCCurveGeometries))
180	0	{
181	0	return TRUE;
182	0	}
183
184	0	return FALSE;
185	0	}
186
187		/************************************************************************/
188		/* GetFeatureCount() */
189		/************************************************************************/
190
191		GIntBig OGRJSONFGStreamedLayer::GetFeatureCount(int bForce)
192	0	{
193	0	if (!m_poFilterGeom && !m_poAttrQuery && nFeatureCount_ >= 0)
194	0	return nFeatureCount_;
195	0	return OGRLayer::GetFeatureCount(bForce);
196	0	}

Coverage Report

Created: 2026-08-14 09:29