ogr_srsnode.cpp

/******************************************************************************
 *
 * Project:  OpenGIS Simple Features Reference Implementation
 * Purpose:  The OGR_SRSNode class.
 * Author:   Frank Warmerdam, warmerdam@pobox.com
 *
 ******************************************************************************
 * Copyright (c) 1999,  Les Technologies SoftMap Inc.
 * Copyright (c) 2010-2013, Even Rouault <even dot rouault at spatialys.com>
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#include "cpl_port.h"
#include "ogr_spatialref.h"

#include <cctype>
#include <cstddef>
#include <cstring>

#include "ogr_core.h"
#include "ogr_p.h"
#include "cpl_conv.h"
#include "cpl_error.h"
#include "cpl_string.h"

/************************************************************************/
/*                            OGR_SRSNode()                             */
/************************************************************************/

/**
 * Constructor.
 *
 * @param pszValueIn this optional parameter can be used to initialize
 * the value of the node upon creation.  If omitted the node will be created
 * with a value of "".  Newly created OGR_SRSNodes have no children.
 */

OGR_SRSNode::OGR_SRSNode(const char *pszValueIn)
    : pszValue(CPLStrdup(pszValueIn)), papoChildNodes(nullptr),
      poParent(nullptr), nChildren(0)
{
}

/************************************************************************/
/*                            ~OGR_SRSNode()                            */
/************************************************************************/

OGR_SRSNode::~OGR_SRSNode()

{
    CPLFree(pszValue);

    ClearChildren();
}

/************************************************************************/
/*                             ~Listener()                              */
/************************************************************************/

OGR_SRSNode::Listener::~Listener() = default;

/************************************************************************/
/*                           RegisterListener()                         */
/************************************************************************/

void OGR_SRSNode::RegisterListener(const std::shared_ptr<Listener> &listener)
{
    m_listener = listener;
}

/************************************************************************/
/*                             notifyChange()                           */
/************************************************************************/

void OGR_SRSNode::notifyChange()
{
    auto locked = m_listener.lock();
    if (locked)
    {
        locked->notifyChange(this);
    }
}

/************************************************************************/
/*                           ClearChildren()                            */
/************************************************************************/

/** Clear children nodes
 */
void OGR_SRSNode::ClearChildren()

{
    for (int i = 0; i < nChildren; i++)
    {
        delete papoChildNodes[i];
    }

    CPLFree(papoChildNodes);

    papoChildNodes = nullptr;
    nChildren = 0;
}

/************************************************************************/
/*                           GetChildCount()                            */
/************************************************************************/

/**
 * \fn int OGR_SRSNode::GetChildCount() const;
 *
 * Get number of children nodes.
 *
 * @return 0 for leaf nodes, or the number of children nodes.
 */

/************************************************************************/
/*                              GetChild()                              */
/************************************************************************/

/**
 * Fetch requested child.
 *
 * @param iChild the index of the child to fetch, from 0 to
 * GetChildCount() - 1.
 *
 * @return a pointer to the child OGR_SRSNode, or NULL if there is no such
 * child.
 */

OGR_SRSNode *OGR_SRSNode::GetChild(int iChild)

{
    if (iChild < 0 || iChild >= nChildren)
        return nullptr;

    return papoChildNodes[iChild];
}

/**
 * Fetch requested child.
 *
 * @param iChild the index of the child to fetch, from 0 to
 * GetChildCount() - 1.
 *
 * @return a pointer to the child OGR_SRSNode, or NULL if there is no such
 * child.
 */

const OGR_SRSNode *OGR_SRSNode::GetChild(int iChild) const

{
    if (iChild < 0 || iChild >= nChildren)
        return nullptr;

    return papoChildNodes[iChild];
}

/************************************************************************/
/*                              GetNode()                               */
/************************************************************************/

/**
 * Find named node in tree.
 *
 * This method does a pre-order traversal of the node tree searching for
 * a node with this exact value (case insensitive), and returns it.  Leaf
 * nodes are not considered, under the assumption that they are just
 * attribute value nodes.
 *
 * If a node appears more than once in the tree (such as UNIT for instance),
 * the first encountered will be returned.  Use GetNode() on a subtree to be
 * more specific.
 *
 * @param pszName the name of the node to search for.
 *
 * @return a pointer to the node found, or NULL if none.
 */

OGR_SRSNode *OGR_SRSNode::GetNode(const char *pszName)

{
    if (nChildren > 0 && EQUAL(pszName, pszValue))
        return this;

    /* -------------------------------------------------------------------- */
    /*      First we check the immediate children so we will get an         */
    /*      immediate child in preference to a subchild.                    */
    /* -------------------------------------------------------------------- */
    for (int i = 0; i < nChildren; i++)
    {
        if (EQUAL(papoChildNodes[i]->pszValue, pszName) &&
            papoChildNodes[i]->nChildren > 0)
            return papoChildNodes[i];
    }

    /* -------------------------------------------------------------------- */
    /*      Then get each child to check their children.                    */
    /* -------------------------------------------------------------------- */
    for (int i = 0; i < nChildren; i++)
    {
        OGR_SRSNode *poNode = papoChildNodes[i]->GetNode(pszName);
        if (poNode != nullptr)
            return poNode;
    }

    return nullptr;
}

/**
 * Find named node in tree.
 *
 * This method does a pre-order traversal of the node tree searching for
 * a node with this exact value (case insensitive), and returns it.  Leaf
 * nodes are not considered, under the assumption that they are just
 * attribute value nodes.
 *
 * If a node appears more than once in the tree (such as UNIT for instance),
 * the first encountered will be returned.  Use GetNode() on a subtree to be
 * more specific.
 *
 * @param pszName the name of the node to search for.
 *
 * @return a pointer to the node found, or NULL if none.
 */

const OGR_SRSNode *OGR_SRSNode::GetNode(const char *pszName) const

{
    return const_cast<OGR_SRSNode *>(this)->GetNode(pszName);
}

/************************************************************************/
/*                              AddChild()                              */
/************************************************************************/

/**
 * Add passed node as a child of target node.
 *
 * Note that ownership of the passed node is assumed by the node on which
 * the method is invoked ... use the Clone() method if the original is to
 * be preserved.  New children are always added at the end of the list.
 *
 * @param poNew the node to add as a child.
 */

void OGR_SRSNode::AddChild(OGR_SRSNode *poNew)

{
    InsertChild(poNew, nChildren);
}

/************************************************************************/
/*                            InsertChild()                             */
/************************************************************************/

/**
 * Insert the passed node as a child of target node, at the indicated
 * position.
 *
 * Note that ownership of the passed node is assumed by the node on which
 * the method is invoked ... use the Clone() method if the original is to
 * be preserved.  All existing children at location iChild and beyond are
 * push down one space to make space for the new child.
 *
 * @param poNew the node to add as a child.
 * @param iChild position to insert, use 0 to insert at the beginning.
 */

void OGR_SRSNode::InsertChild(OGR_SRSNode *poNew, int iChild)

{
    if (iChild > nChildren)
        iChild = nChildren;

    nChildren++;
    papoChildNodes = static_cast<OGR_SRSNode **>(
        CPLRealloc(papoChildNodes, sizeof(void *) * nChildren));

    memmove(papoChildNodes + iChild + 1, papoChildNodes + iChild,
            sizeof(void *) * (nChildren - iChild - 1));

    papoChildNodes[iChild] = poNew;
    poNew->poParent = this;

    poNew->m_listener = m_listener;
    notifyChange();
}

/************************************************************************/
/*                            DestroyChild()                            */
/************************************************************************/

/**
 * Remove a child node, and it's subtree.
 *
 * Note that removing a child node will result in children after it
 * being renumbered down one.
 *
 * @param iChild the index of the child.
 */

void OGR_SRSNode::DestroyChild(int iChild)

{
    if (iChild < 0 || iChild >= nChildren)
        return;

    delete papoChildNodes[iChild];
    while (iChild < nChildren - 1)
    {
        papoChildNodes[iChild] = papoChildNodes[iChild + 1];
        iChild++;
    }

    nChildren--;
    notifyChange();
}

/************************************************************************/
/*                             FindChild()                              */
/************************************************************************/

/**
 * Find the index of the child matching the given string.
 *
 * Note that the node value must match pszValue with the exception of
 * case.  The comparison is case insensitive.
 *
 * @param pszValueIn the node value being searched for.
 *
 * @return the child index, or -1 on failure.
 */

int OGR_SRSNode::FindChild(const char *pszValueIn) const

{
    for (int i = 0; i < nChildren; i++)
    {
        if (EQUAL(papoChildNodes[i]->pszValue, pszValueIn))
            return i;
    }

    return -1;
}

/************************************************************************/
/*                              GetValue()                              */
/************************************************************************/

/**
 * \fn const char *OGR_SRSNode::GetValue() const;
 *
 * Fetch value string for this node.
 *
 * @return A non-NULL string is always returned.  The returned pointer is to
 * the internal value of this node, and should not be modified, or freed.
 */

/************************************************************************/
/*                              SetValue()                              */
/************************************************************************/

/**
 * Set the node value.
 *
 * @param pszNewValue the new value to assign to this node.  The passed
 * string is duplicated and remains the responsibility of the caller.
 */

void OGR_SRSNode::SetValue(const char *pszNewValue)

{
    CPLFree(pszValue);
    pszValue = CPLStrdup(pszNewValue);
    notifyChange();
}

/************************************************************************/
/*                               Clone()                                */
/************************************************************************/

/**
 * Make a duplicate of this node, and it's children.
 *
 * @return a new node tree, which becomes the responsibility of the caller.
 */

OGR_SRSNode *OGR_SRSNode::Clone() const

{
    OGR_SRSNode *poNew = new OGR_SRSNode(pszValue);

    for (int i = 0; i < nChildren; i++)
    {
        poNew->AddChild(papoChildNodes[i]->Clone());
    }
    poNew->m_listener = m_listener;

    return poNew;
}

/************************************************************************/
/*                            NeedsQuoting()                            */
/*                                                                      */
/*      Does this node need to be quoted when it is exported to Wkt?    */
/************************************************************************/

int OGR_SRSNode::NeedsQuoting() const

{
    // Non-terminals are never quoted.
    if (GetChildCount() != 0)
        return FALSE;

    // As per bugzilla bug 201, the OGC spec says the authority code
    // needs to be quoted even though it appears well behaved.
    if (poParent != nullptr && EQUAL(poParent->GetValue(), "AUTHORITY"))
        return TRUE;

    // As per bugzilla bug 294, the OGC spec says the direction
    // values for the AXIS keywords should *not* be quoted.
    if (poParent != nullptr && EQUAL(poParent->GetValue(), "AXIS") &&
        this != poParent->GetChild(0))
        return FALSE;

    if (poParent != nullptr && EQUAL(poParent->GetValue(), "CS") &&
        this == poParent->GetChild(0))
        return FALSE;

    // Strings starting with e or E are not valid numeric values, so they
    // need quoting, like in AXIS["E",EAST]
    if ((pszValue[0] == 'e' || pszValue[0] == 'E'))
        return TRUE;

    // Non-numeric tokens are generally quoted while clean numeric values
    // are generally not.
    for (int i = 0; pszValue[i] != '\0'; i++)
    {
        if ((pszValue[i] < '0' || pszValue[i] > '9') && pszValue[i] != '.' &&
            pszValue[i] != '-' && pszValue[i] != '+' && pszValue[i] != 'e' &&
            pszValue[i] != 'E')
            return TRUE;
    }

    return FALSE;
}

/************************************************************************/
/*                            exportToWkt()                             */
/************************************************************************/

/**
 * Convert this tree of nodes into WKT format.
 *
 * Note that the returned WKT string should be freed with
 * CPLFree() when no longer needed.  It is the responsibility of the caller.
 *
 * @param ppszResult the resulting string is returned in this pointer.
 *
 * @return currently OGRERR_NONE is always returned, but the future it
 * is possible error conditions will develop.
 */

OGRErr OGR_SRSNode::exportToWkt(char **ppszResult) const

{
    /* -------------------------------------------------------------------- */
    /*      Build a list of the WKT format for the children.                */
    /* -------------------------------------------------------------------- */
    char **papszChildrenWkt =
        static_cast<char **>(CPLCalloc(sizeof(char *), nChildren + 1));
    size_t nLength = strlen(pszValue) + 4;

    for (int i = 0; i < nChildren; i++)
    {
        papoChildNodes[i]->exportToWkt(papszChildrenWkt + i);
        nLength += strlen(papszChildrenWkt[i]) + 1;
    }

    /* -------------------------------------------------------------------- */
    /*      Allocate the result string.                                     */
    /* -------------------------------------------------------------------- */
    *ppszResult = static_cast<char *>(CPLMalloc(nLength));
    *ppszResult[0] = '\0';

    /* -------------------------------------------------------------------- */
    /*      Capture this nodes value.  We put it in double quotes if        */
    /*      this is a leaf node, otherwise we assume it is a well formed    */
    /*      node name.                                                      */
    /* -------------------------------------------------------------------- */
    if (NeedsQuoting())
    {
        strcat(*ppszResult, "\"");
        strcat(*ppszResult, pszValue);  // Should we do quoting?
        strcat(*ppszResult, "\"");
    }
    else
        strcat(*ppszResult, pszValue);

    /* -------------------------------------------------------------------- */
    /*      Add the children strings with appropriate brackets and commas.  */
    /* -------------------------------------------------------------------- */
    if (nChildren > 0)
        strcat(*ppszResult, "[");

    for (int i = 0; i < nChildren; i++)
    {
        strcat(*ppszResult, papszChildrenWkt[i]);
        if (i == nChildren - 1)
            strcat(*ppszResult, "]");
        else
            strcat(*ppszResult, ",");
    }

    CSLDestroy(papszChildrenWkt);

    return OGRERR_NONE;
}

/************************************************************************/
/*                         exportToPrettyWkt()                          */
/************************************************************************/

/**
 * Convert this tree of nodes into pretty WKT format.
 *
 * Note that the returned WKT string should be freed with
 * CPLFree() when no longer needed.  It is the responsibility of the caller.
 *
 * @param ppszResult the resulting string is returned in this pointer.
 *
 * @param nDepth depth of the node
 *
 * @return currently OGRERR_NONE is always returned, but the future it
 * is possible error conditions will develop.
 */

OGRErr OGR_SRSNode::exportToPrettyWkt(char **ppszResult, int nDepth) const

{
    /* -------------------------------------------------------------------- */
    /*      Build a list of the WKT format for the children.                */
    /* -------------------------------------------------------------------- */
    char **papszChildrenWkt =
        static_cast<char **>(CPLCalloc(sizeof(char *), nChildren + 1));
    size_t nLength = strlen(pszValue) + 4;

    for (int i = 0; i < nChildren; i++)
    {
        papoChildNodes[i]->exportToPrettyWkt(papszChildrenWkt + i, nDepth + 1);
        nLength += strlen(papszChildrenWkt[i]) + 2 + nDepth * 4;
    }

    /* -------------------------------------------------------------------- */
    /*      Allocate the result string.                                     */
    /* -------------------------------------------------------------------- */
    *ppszResult = static_cast<char *>(CPLMalloc(nLength));
    *ppszResult[0] = '\0';

    /* -------------------------------------------------------------------- */
    /*      Capture this nodes value.  We put it in double quotes if        */
    /*      this is a leaf node, otherwise we assume it is a well formed    */
    /*      node name.                                                      */
    /* -------------------------------------------------------------------- */
    if (NeedsQuoting())
    {
        strcat(*ppszResult, "\"");
        strcat(*ppszResult, pszValue);  // Should we do quoting?
        strcat(*ppszResult, "\"");
    }
    else
    {
        strcat(*ppszResult, pszValue);
    }

    /* -------------------------------------------------------------------- */
    /*      Add the children strings with appropriate brackets and commas.  */
    /* -------------------------------------------------------------------- */
    if (nChildren > 0)
        strcat(*ppszResult, "[");

    for (int i = 0; i < nChildren; i++)
    {
        if (papoChildNodes[i]->GetChildCount() > 0)
        {
            strcat(*ppszResult, "\n");
            for (int j = 0; j < 4 * nDepth; j++)
                strcat(*ppszResult, " ");
        }
        strcat(*ppszResult, papszChildrenWkt[i]);
        if (i < nChildren - 1)
            strcat(*ppszResult, ",");
    }

    if (nChildren > 0)
    {
        if ((*ppszResult)[strlen(*ppszResult) - 1] == ',')
            (*ppszResult)[strlen(*ppszResult) - 1] = '\0';

        strcat(*ppszResult, "]");
    }

    CSLDestroy(papszChildrenWkt);

    return OGRERR_NONE;
}

/************************************************************************/
/*                           importFromWkt()                            */
/************************************************************************/

/**
 * Import from WKT string.
 *
 * This method will wipe the existing children and value of this node, and
 * reassign them based on the contents of the passed WKT string.  Only as
 * much of the input string as needed to construct this node, and its
 * children is consumed from the input string, and the input string pointer
 * is then updated to point to the remaining (unused) input.
 *
 * @param ppszInput Pointer to pointer to input.  The pointer is updated to
 * point to remaining unused input text.
 *
 * @return OGRERR_NONE if import succeeds, or OGRERR_CORRUPT_DATA if it
 * fails for any reason.
 * @deprecated GDAL 2.3. Use importFromWkt(const char**) instead.
 */

OGRErr OGR_SRSNode::importFromWkt(char **ppszInput)

{
    int nNodes = 0;
    return importFromWkt(const_cast<const char **>(ppszInput), 0, &nNodes);
}

/**
 * Import from WKT string.
 *
 * This method will wipe the existing children and value of this node, and
 * reassign them based on the contents of the passed WKT string.  Only as
 * much of the input string as needed to construct this node, and its
 * children is consumed from the input string, and the input string pointer
 * is then updated to point to the remaining (unused) input.
 *
 * @param ppszInput Pointer to pointer to input.  The pointer is updated to
 * point to remaining unused input text.
 *
 * @return OGRERR_NONE if import succeeds, or OGRERR_CORRUPT_DATA if it
 * fails for any reason.
 *
 * @since GDAL 2.3
 */

OGRErr OGR_SRSNode::importFromWkt(const char **ppszInput)

{
    int nNodes = 0;
    return importFromWkt(ppszInput, 0, &nNodes);
}

OGRErr OGR_SRSNode::importFromWkt(const char **ppszInput, int nRecLevel,
                                  int *pnNodes)

{
    // Sanity checks.
    if (nRecLevel == 10)
    {
        return OGRERR_CORRUPT_DATA;
    }
    if (*pnNodes == 1000)
    {
        return OGRERR_CORRUPT_DATA;
    }

    const char *pszInput = *ppszInput;
    bool bInQuotedString = false;

    /* -------------------------------------------------------------------- */
    /*      Clear any existing children of this node.                       */
    /* -------------------------------------------------------------------- */
    ClearChildren();

    /* -------------------------------------------------------------------- */
    /*      Read the ``value'' for this node.                               */
    /* -------------------------------------------------------------------- */
    {
        char szToken[512];  // do not initialize whole buffer. significant
                            // overhead
        size_t nTokenLen = 0;
        szToken[0] = '\0';

        while (*pszInput != '\0' && nTokenLen + 1 < sizeof(szToken))
        {
            if (*pszInput == '"')
            {
                bInQuotedString = !bInQuotedString;
            }
            else if (!bInQuotedString &&
                     (*pszInput == '[' || *pszInput == ']' ||
                      *pszInput == ',' || *pszInput == '(' || *pszInput == ')'))
            {
                break;
            }
            else if (!bInQuotedString &&
                     (*pszInput == ' ' || *pszInput == '\t' ||
                      *pszInput == 10 || *pszInput == 13))
            {
                // Skip over whitespace.
            }
            else
            {
                szToken[nTokenLen++] = *pszInput;
            }

            pszInput++;
        }

        if (*pszInput == '\0' || nTokenLen == sizeof(szToken) - 1)
            return OGRERR_CORRUPT_DATA;

        szToken[nTokenLen++] = '\0';
        SetValue(szToken);
    }

    /* -------------------------------------------------------------------- */
    /*      Read children, if we have a sublist.                            */
    /* -------------------------------------------------------------------- */
    if (*pszInput == '[' || *pszInput == '(')
    {
        do
        {
            pszInput++;  // Skip bracket or comma.

            OGR_SRSNode *poNewChild = new OGR_SRSNode();
            poNewChild->m_listener = m_listener;

            (*pnNodes)++;
            const OGRErr eErr =
                poNewChild->importFromWkt(&pszInput, nRecLevel + 1, pnNodes);
            if (eErr != OGRERR_NONE)
            {
                delete poNewChild;
                return eErr;
            }

            AddChild(poNewChild);

            // Swallow whitespace.
            while (isspace(static_cast<unsigned char>(*pszInput)))
                pszInput++;
        } while (*pszInput == ',');

        if (*pszInput != ')' && *pszInput != ']')
            return OGRERR_CORRUPT_DATA;

        pszInput++;
    }

    *ppszInput = pszInput;

    return OGRERR_NONE;
}

/************************************************************************/
/*                           MakeValueSafe()                            */
/************************************************************************/

/**
 * Massage value string, stripping special characters so it will be a
 * database safe string.
 *
 * The operation is also applies to all subnodes of the current node.
 */

void OGR_SRSNode::MakeValueSafe()

{
    /* -------------------------------------------------------------------- */
    /*      First process subnodes.                                         */
    /* -------------------------------------------------------------------- */
    for (int iChild = 0; iChild < GetChildCount(); iChild++)
    {
        GetChild(iChild)->MakeValueSafe();
    }

    /* -------------------------------------------------------------------- */
    /*      Skip numeric nodes.                                             */
    /* -------------------------------------------------------------------- */
    if ((pszValue[0] >= '0' && pszValue[0] <= '9') || pszValue[0] != '.')
        return;

    /* -------------------------------------------------------------------- */
    /*      Translate non-alphanumeric values to underscores.               */
    /* -------------------------------------------------------------------- */
    for (int i = 0; pszValue[i] != '\0'; i++)
    {
        if (!(pszValue[i] >= 'A' && pszValue[i] <= 'Z') &&
            !(pszValue[i] >= 'a' && pszValue[i] <= 'z') &&
            !(pszValue[i] >= '0' && pszValue[i] <= '9'))
        {
            pszValue[i] = '_';
        }
    }

    /* -------------------------------------------------------------------- */
    /*      Remove repeated and trailing underscores.                       */
    /* -------------------------------------------------------------------- */
    int j = 0;
    for (int i = 1; pszValue[i] != '\0'; i++)
    {
        if (pszValue[j] == '_' && pszValue[i] == '_')
            continue;

        pszValue[++j] = pszValue[i];
    }

    if (pszValue[j] == '_')
        pszValue[j] = '\0';
    else
        pszValue[j + 1] = '\0';
}

/************************************************************************/
/*                             StripNodes()                             */
/************************************************************************/

/**
 * Strip child nodes matching name.
 *
 * Removes any descendant nodes of this node that match the given name.
 * Of course children of removed nodes are also discarded.
 *
 * @param pszName the name for nodes that should be removed.
 */

void OGR_SRSNode::StripNodes(const char *pszName)

{
    /* -------------------------------------------------------------------- */
    /*      Strip any children matching this name.                          */
    /* -------------------------------------------------------------------- */
    while (FindChild(pszName) >= 0)
        DestroyChild(FindChild(pszName));

    /* -------------------------------------------------------------------- */
    /*      Recurse                                                         */
    /* -------------------------------------------------------------------- */
    for (int i = 0; i < GetChildCount(); i++)
        GetChild(i)->StripNodes(pszName);
}